The Speedway in its current form (read that to = slow, meandering cars), turned into a Sugar Rush overlay (read that to = an actual fast paced "race" style ride), would have to be significantly revamped to include more responsive electric cars that 1. Go over 3 miles and hour, and 2. Actually feel like you're driving and/or piloting a race car. The only way to pull this off would be to completely automate the ride and take the control away from the driver (i.e. mission space "push this button..NOW!" type controls).
or, they could just put some screenz up of the movie here and there and blow some wind in your face to create the effect of "going fast", pipe in some peppermint candy scent when cars crash in front of you (on the screenz), and call it a day.