Miracle in Lane 2 (2000)

Myron Yoder's Indiana family always was proud of eldest son Seth, a sports prodigy, but most attention goes to younger Justin, whose spina bifida condition means a wheelchair and constant, frantic care. During make-up chores for endangering grumpy neighbor Vic Sauder's sports car, Justin discovers a sport he finally hopes to excel in, soap box cart racing, and gets highly experienced Vic and pa to help and coach him. That proves promising and dangerous, but also puts unbearable stress on the family cohesion as Seth now feels cruelly shoved aside.