Building a 40-Meter Mousetrap Car: Tips for Optimal String Attachment

[lightfire22000]

I have to build a mousetrap car that goes at least 40 meters. I know the design should be one big wheel in back, and two small wheels in front. Design aside, anybody have any advice on how to attach the string from the mousetrap to the axel optimally?

Should I just wrap the string around the axel and the mousetrap, or should I build a loop on the axel?

 

[andrevdh]

Is the snap action of the trap suppose to drive the car in one go?