fig1 shows an inventive device which is designated in total by reference numeral 1 . the device 1 serves for adjusting the gap dimensions and / or the offset between a movable flap 2 of a vehicle and the remaining body 3 of the vehicle . fig1 shows a vertical section through the vehicle , transverse to a longitudinal vehicle axis . the movable flap 2 in this example is a motor hood or a trunk lid . the remaining body 3 of the vehicle is represented by the fenders . the movable flap 2 is initially mounted to the remaining body 3 in a roughly adjusted installation position via hinges or joints such that the flap 2 can be rotated about an axis of rotation . the movable flap 2 is fitted in the roughly adjusted installation position in a special installation space of the body 3 , preferably using an industrial robot or other manipulation device . the movable flap 2 , fitted in the roughly adjusted installation position , is held by the hinges and optionally also by the industrial robot or the manipulation device . after rough adjustment , the flap 2 must be fitted into the installation space of the body 3 into a finely adjusted installation position . fine adjustment is required to be able to exactly maintain specified values of the gap dimensions and / or the offset . this is particularly important , since inaccurate gap dimensions or excessive offset of the flap 2 relative to the remaining body 3 of a vehicle can produce disturbing wind noises during travel . moreover , the visual impression of the vehicle to the viewer would be impaired by irregular gap dimensions or excessive offset . this applies , in particular , to vehicles having decorative strips or vehicle lights which do not border a gap , but which extend to both sides of the gap . in such cases , an irregular or excessive gap or offset would be particularly noticeable . after fine adjustment of the flap 2 relative to the remaining body 3 , the flap 2 is either fixed on the body 3 in the finely adjusted installation position or is removed , e . g . for separate painting of the flaps 2 and body 3 . in the latter case , fitting of the flap 2 into the remaining body 3 merely serves to determine whether or not the shape of the flap 2 or of the remaining body permits satisfactory installation of the flap 2 into the provided installation space of the body 3 during later final assembly , thereby observing the specified desired values for the gap dimensions and / or offset . the inventive method concerns , in particular , fine adjustment of the movable flap 2 relative to the remaining body 3 of the vehicle . the inventive device 1 comprises detection means 4 having an image detection means 8 which is preferably designed as ccd ( charged coupled device ) camera or as cmos ( complimentary metal oxide semiconductor ) camera ( see fig2 ). the detection means 4 serve for optical detection of the actual values for the gap dimensions and / or the offset between the roughly adjusted flap 2 and the remaining body 3 . the detection means 4 are explained in more detail below with reference to fig2 . detection means 4 are designed as a camera laser unit or as a so - called laser sensor , and comprise a carrier element 5 to which the image detection means 8 is mounted . an illumination means 6 is additionally mounted to the carrier element 5 to illuminate a measuring location 7 in the region of a transition between the flap 2 and the remaining body 3 and / or images a pattern on the surfaces to be detected at the measuring location 7 . the illumination means 6 is designed e . g . as a laser . it is theoretically sufficient for the detection means 4 to comprise only one optical image detection means 8 . the illumination means 6 which illuminates the measuring location 7 and provides it with a pattern considerably facilitates detection of the gap dimensions and / or of the offset between the flap 3 and the remaining body 2 , thereby also improving the accuracy . in the embodiment of fig2 , the laser 6 generates a sharply defined light line 9 in the region of the measuring location 7 , which extends across the gap , from the flap 2 and the body 3 . the illumination means 6 could , of course , also generate light lines extending parallel to the gap at the facing edges of the flap 2 and body 3 , as is disclosed e . g . in de 199 10 699 or the corresponding u . s . pat . no . 6 , 529 , 283 . in accordance with the invention , any method for detecting the transition between the flap 2 and the body 3 may be used . the detection means 4 are mounted to a distal end of an industrial robot arm 10 or to any other manipulation device . the robot or the manipulation device moves the detection means 4 to predetermined measuring locations 7 for detecting the actual values of the gap dimensions and / or the offset between the flap 3 of the vehicle and the remaining body 2 , at that location . the device 1 also comprises ( see fig1 ) computing means 11 which are preferably designed in the form of a personal computer ( pc ). the computing means 11 comprise an electronic storage element 26 on which a computer program is stored and which is programmed to perform the inventive method . the storage element 26 is preferably a flash storage . in order to run the computer program , it is transferred to a computing device 28 via a data connection , either completely , in sections or corresponding to commands . the computing device 28 is preferably designed as a microprocessor . the computing means 11 serve i . a . to generate drive signals 24 for actuating elements 12 . the drive signals 24 are determined in dependence on the detected actual values 21 ist for the gap dimensions and / or the offset between the roughly adjusted flap 2 and the remaining body 3 and in dependence on the predetermined desired values 21 soll for the gap dimensions and / or the offset . the actual values 21 ist detected by the detection means 4 are transferred to the computing means via data lines 13 . the drive signals 24 generated by the computing means 11 are transferred to the actuating elements 12 via data lines 14 . the actuating elements 12 vary the relative position and orientation between the flap 2 and the remaining body 3 . the actuating elements 12 preferably move the flap 2 about the axis of rotation defined by the hinges or joints via which the flap 2 is mounted to the body 3 . in the present embodiment , the actuating elements 12 are formed as electric linear motors or stepping motors which act on the flap 2 at effective points 15 to vary the position and orientation of the flap 2 relative to the remaining body 3 . the actuating elements 12 or the effective points 15 are preferably disposed on a side of the flap 2 opposite to the hinges or joints . the actuating elements 12 can move the flap upwards and downwards and preferably also to the left and right ( fig1 ). the transition between the flap 2 and the remaining body 3 is determined by the gap dimensions and / or the offset of the flap 2 relative to the remaining body 3 . the transition may be defined either as subjective impression of one or more observer / s ( e . g . the members of staff responsible for quality assurance ) or objectively through a certain mathematical description . a mathematical description of the transition is e . g . disclosed in u . s . pat . no . 4 , 498 , 776 , u . s . pat . no . 4 , 666 , 303 , u . s . pat . no . 5 , 416 , 590 and u . s . pat . no . 5 , 999 , 265 . these documents disclose different possible analytic descriptions of the transition between two parts , preferably between a flap and the remaining vehicle body and are hereby incorporated by reference with respect to their mathematical definition of a transition . of course , there are many other feasible analytical descriptions of a transition . fig3 illustrates a situation in which the separation 21 between a measuring straight line 20 contacting the surface of the remaining body 3 and the surface of the flap 2 is substantially less than zero , i . e . the transition amount is relatively large . to correct this negative transition , the flap 2 is moved in a controlled manner in the direction of arrow 12 ′ by the actuating elements 12 in accordance with the invention until the separation 21 has reached a specified desired value , preferably zero . reference numeral 16 designates a first function for extrapolating a surface of the flap 2 beyond its end . reference numeral 17 designates a second function for extrapolating a surface of the body 3 beyond its end . the intersection between the two functions 16 , 17 is designated with reference numeral 18 . reference numeral 19 designates a vertical straight line which bisects the opening angle between the functions 16 , 17 . reference numeral 20 designates the measuring straight line which intersects the vertical straight line 19 at right angles and which tangentially contacts the surface of the body 3 . fig4 shows the flap 2 in its finely adjusted installation position after termination of fine adjustment . the separation 21 has been reduced to almost zero through inventive regulation of the installation position . fig5 to 7 show different images recorded by the optical detection means 4 in the region of a measuring location 7 . fig5 shows the image recorded by a laser sensor with a transition of − 5 mm . fig6 shows the same image , however , with a transition of 0 mm , and fig7 shows the same image , however , with a transition of + 5 mm . the images recorded by the optical detection means 4 in accordance with fig5 through 7 are evaluated in the computing means 11 to detect the transition ( gap dimension and / or offset ) between the flap 2 and the remaining body 3 at the measuring location 7 . the computing means 11 then generate the drive signals 24 for the actuating elements 12 in dependence on the detected actual values 21 ist and in dependence on the specified desired values 21 soll ( preferably to a zero transition ). fig8 shows a control loop structure to explain the inventive method . the detection means 4 ( laser sensor ) detect an actual value of the transition 21 ist and the measured actual value 21 ist is subtracted from a specified desired value for the transition 21 soll . a transition = 0 is preferably preset as desired value 21 soll . the difference between the desired and actual values is called the control deviation 22 . the control deviation 22 is supplied to a regulation means 23 which is preferably realized in the form of software . towards this end , a corresponding computer program is run on the computing means 11 of the device 1 . the regulation means 23 generate the drive signals 24 for the actuating elements 12 on the basis of the control deviation 22 . the drive signals 24 therefore constitute the controlled variable for regulation . driving the actuating elements 12 with the generated drive signals 24 causes displacement of the flap 2 relative to the remaining body 3 ( position and / or orientation ) by a certain amount . this displacement of the flap 2 is symbolized by an operational block 25 . displacement 25 of the flap 2 produces a new actual value 21 ist of the transition which is , in turn , detected by the detection means 4 . repeated run of the control loop structure of fig8 causes approximation of the actual value 21 ist of the transition to the specified desired value 21 soll of the transition . if the desired deviation is zero , the control loop structure is run until the actual value 21 ist of the transition is equal to the desired value 21 soll of the transition .