[blykins]

What I did was mount the body, then take the wheels and tires off the car. Hang plum bobs from the center of the fenders so they fall down directly in front of the wheel hubs/rotors. If you don't have a plub bob, just use some string with some weights on the end. I think I just tied some sockets on the end of some regular string and did it.

Then just measure on each corner from the string to the wheel hub. Get the rears matching and the fronts matching and you got it.

Also, you can use the bumper holes to judge how straight you are....the holes in the frame should line up directly with the holes in the body.