Mousetrap Vehicle

Overview
Mousetrap vehicle is a car that you must design to go forward x amount of meters and come back to its original starting point.You will be allowed two un-modified mousetraps which means that the mousetraps must have all the original parts

How to Make it Work
There are three easy designs to get it to come back one mousetrap on each axle you wind one mousetrap up and as it goes down it winds the other mousetrap up to pull it back normally to do this model you need to add a bar to your mousetrap to make it have more leverage to make it go the x amount of meters

Two mousetraps on one axle with the other axle having a piece of rubber that gets stretched as you go the x amount of meters and will send it back to the beginning also normally you need to add a bar to your mousetrap to make it have more leverage to make it go the x amount of meters

the last model and what i think to be the easiest is to have two mousetraps connected to the axle and you wind it x amount of times and than wrap it around a pin on the axle and continue wrapping it the opisete way that you started normally you need to add a bar to your mousetrap to make it have more leverage to make it go the x amount of meters

also you need to have the string come of of the axle or you will start to head back towards the x amount of meters mark

Number of Turns
To figure out the number of turns need all you must do is get the circumferance of your wheels that are being driven and divide the distance by circumference