Sorry to hear about your disappointment Vehicles that work best on Hot Wheels Track Sets are regular 1:64 scale sports cars or sedans. Vehicles that usually do not work best are vans, trucks, or buses; anything too bulky or heavy. Part of the fun is figuring out which cars work best with the race set. It may take some practice and trial 'n error before you find the ones that run the fastest or always completes the track. Then you know you’ve got real winners. Don't hesitate to reach out to our Customer Service Team at 800-524-8697, Mon.- Fri., 9am - 6pm EST if you experience any quality issues.