for several year , I have envy the owner of high end car equip with navigation system . I consider get a aftermarket in-dash system , but the price be too steep . the StreetPilot III Deluxe be just what I have be look for . it be a reliable , well-designed , and just plain fun gadget that will please the electronics junkie and the casual user alike .  the high resolution screen be gorgeous and remain clearly visible even in bright sunlight . at sundown -lrb- automatically calculate by the StreetPilot -rrb- , the display switch to black and white and can still be read easily without distract the driver . operation be very easy once you get the hang of it . the 128 mb datum card include with the deluxe version can store map cover a radius of 500 + mile . it should be adequate for almost all trip . program the card be fairly easy , although the software be probably the system 's weakest link . the interface be poorly design but functional .  the system 's autorouting function work very well , but because it can not account for traffic volume or terrain , it sometimes underestimate drive time and thus do not choose the quickest route . 95 % of the time , however , the system choose the best route , and it have identify new and better direction for several of my most common trip . the vocal prompt be excellent . a sophisticated trip computer be a include feature and be a welcome addition if you car do not have one .  I can not praise the StreetPilot highly enough . in many way , I think it be superior to a in-dash system , in term of price and portability -lrb- since you can transfer the device between car -rrb- . it be the rare gadget that be both useful and fun . you 'll wonder how you ever live without it .