That sort of defeats the purpose of shuffle racing. As I understood it the idea was that the faster guys ended up and cars that were significantly off the pace and use their superior skill set to overcome the deficiencies of the car. If the cars are balanced that means you get a random car but the fastest drivers will still always win.
What might make it work is if the cars were nerfed slighty, perhaps with a little less aero and power for the faster guys.