I am using a protoform mulsanne,with glued on stabilizers,and it is pretty stable at 60+++mph.Some guys use a stock car body.Think about this.You want to create the smallest hole int the air as possible.The mulsanne-as low as it sits is wide.It might have a overall larger frontal surface area than a taller,but narrower stock car body.I have had reasonable sucess with a hpi new style camaro and firebird ta.