Good rule of thumb is installing the anchoring point at camshaft level. Too low and you lift the rear of the car when the chute fills, too high and the front tires loose steering traction.
http://www.dragstuff.com/techarticles/parachutes.html
http://stroudsafety.com/DragChutes.html
http://www.simpsonraceproducts.com/safety-chutes/