Mousetrap car

The skewers wouldn't be a substantial modification but it would be a dramatic improvement. I've made mousetrap cars before using that technique and it's much easier and faster. Also you'd have to tape the end of the string to the end of the skewers but that wouldn't affect much, just turn the wheels to wind the string. Also, I don't think the problem is winding the string.

When your car runs does the mousetrap go off really quickly and kind of jerks the car to move?

It goes off really quickly.