Babies and toddlers with disabilities have a slightly higher incidence of back-seat, car-seat, and other car travel meltdowns than their mainstream peers. Transition, sensory issues, discomfort and panic can cause distress leading to habitual avoidance of travel for children with many appointments.

Car Travel Meltdowns - Babies and Toddlers
http://www.bellaonline.com/articles/art182437.asp