vehicle vs wall

let's say you drive a 4 wheel rc car towards a wall. what's the force required to drive the front wheels up the wall?

i've been told that each tire needs to produce LESS than 1/4 the total weight of the car. i just can't work it out that way.

this is a design project problem. they don't make motors torquey enough to produce 1/4 the weight of my little car, but it's close. if it's slightly less, i'm saved and i can find some motors. see if you guys can work this out better than i can. save my life.

You won't be able to drive the front wheels up the wall. Why, you ask? It's simple. If you crash into a brick wall at any speed, the force generated will cause the back of your car to be thrown in the air, resulting in the front of the car being pressed downwards.