Children with mobility disabilities have more limited opportunities to explore their environment; therefore, they are considered to be at risk of secondary impairments, such as cognitive, spatial-perceptual, and social-emotional delay. Independent mobility is believed to be essential for perceptual-motor and social skills development. Self-produced locomotion is an organizer of psychological changes in typically developing infants/children, especially developmental changes in perceptions, social understanding, spatial cognitive, and emotions. Power mobility devices provide the potential for children with disabilities to move more independently and increase their exploration and interaction with the social and physical environment. Through the exploration, infants can detect the object and individual‟s information that relates size, orientation, shape, substance to their perceptual and movement capabilities and interpersonal relationships. Logically, starting powered mobility as part of a comprehensive Early Intervention (EI) program within the first year of life should not only provide mobility but also reduce secondary impairments for children with disabilities. Although of increasing interest, there is very little empirical evidence of the effects or even feasibility of early power mobility training on development, particularly for mobility and socialization. A hallmark of daily life for the typically developing infants and toddlers is hours of mobility nested within exploration, socialization and object play in the home and community.Pediatric rehabilitation, through training and assistive technology (AT), seeks to provide children with disabilities with this same level of mobility, exploration and socialization. There are many basic barriers to achieving this high standard and no single AT or combination of AT can currently provide the level of mobility that children, families and therapists desire. For example, certain characteristics of the most common commercial pediatric power wheelchairs limit their use in the home and community spaces such as playgrounds. These limitations include price (e.g., typically $5000), size and weight (e.g., typically >150 lbs), transportation requirements (e.g., van or truck), maintenance and aesthetics and social acceptance. The most obvious limitation for including power mobility in EI programs is the complete lack of readily available power chairs for children younger than 2-3 years of age, the period when mobility is rapidly developing for typically developing children. Experimental power mobility devices have the potential to address some of these limitations such as size, weight and infant use. Unfortunately these are likely years from commercial availability. Furthermore, power wheelchairs have historically been designed to address a limited set of goals related to mobility with minimal consideration of socialization. Investigators believe there is a need for readily available mobility options for immediate use by very young children and their families that address some of the above limitations while expanding the role of power devices past simply mobility and into socialization. The general purpose of this study is to determine the feasibility of using a "ride-on toy car" as an early option for power mobility. Furthermore, this study will examine the effects of using a toy car to advance mobility and socialization in the early development. The use of modified ride-on toy cars may provide a readily available, convenient and fun way for families, therapists and early educators to help young children improve their mobility starting within the first years of life. There are four strengths of using ride-on toy cars for mobility. First, the cost is comparable or less than most mobility devices. Second, most are relatively lightweight, small and easily transported in contrast to power chairs. Third, the child-friendly, colorful toy designs are more acceptable to adults and children and likely seen as simply a toy. This may be an important aspect for clinicians wanting to start early power mobility training with families hesitant to discuss powered chair options. Fourth, because toy cars are simple electromachanical devices, they can be modified quickly and easily to match the child's current and/or future abilities and goals. Ride-on cars provide fun and mobility for typically developing children and have serious potential to be a power mobility option for children with disabilities. Investigators have recently published a technical report outing the basic components and exemplar modifications. Our pilot study has also shown positive effects on increased socialization in a 2-year old child with severe cerebral palsy. No studies have been published on the effectiveness or even the feasibility of including these cars with any pediatric population. Thus basic questions such as sitting tolerance, basic driving ability and interest in using the car for socialization have not been addressed prior to wide spread clinical use. The long term effects of using this mobility device on mobility and socialization also remain a question for the researchers and clinicians. In addition, little is known about the learning curve of using the power mobility device to improve mobility and socialization, e.g., at what point in time (maximal) effects are reached. Up to now, most of the studies have focused on the end results of increased amount of independent mobility in daily life. It is still unknown whether optimal (maximal) effects are being reached at all and which factors (e.g., training environment, training executor) might influence the learning curve as well as the retention of treatment effects in the long term. In the study by Tieman et al. (2004), they suggested that therapists should examine children's performances in the settings that are important to their daily life. Examining performance in everyday settings enables the therapists not only to observe the child's ability, but also to assess environmental features that either facilitate or hinder mobility. Our study will focus on providing intervention and exploratory assessments in the home or a clinical setting. This information is essential for making future decisions on whether interventions should focus on the child‟s motor ability in a therapeutic environment from the therapist's perspective, or adaptation of the natural environment for the caregiver's application. In this study, investigators will modify ride-on toy cars for children with disabilities for use in the clinical settings as part of a 18-week power mobility training program. Investigators focus on four basic questions. Specifically, can investigators: 1) select and modify toy cars such that children with motor impairments enjoy sitting and driving, 2) select a set of dependent measures that quantify whether the children increase their independent mobility and socialization; 3) determine the factors that influence the learning curve of independent mobility and socialization during intervention and follow-up phases; 4) conduct a hospital-based training program that results in a high level of fun for the child and compliance by the family and therapists. If our results are generally positive and show significant differences between different programs, then future randomized controlled trial studies could further quantify the effectiveness and the feasibility with different treatment intensity and various pediatric populations.