Unless your planning to cut 1/2 the body away It wont fit The rear of the audi being too low,I tried to get one in for my Wrexham audi challenge car no luck ,The hsr chassis with side windwinder mount in a proslot porsche is a good choice , I ran one to 4th oa in last yrs pendle porsche challenge despite being quite ill that day the car did most of the work , My spare car which I lent to chris crewe finished 2nd team orders were ignored ( chris works for me ) and my cries of pass me and your sacked fell on deaf ears ( chris still works for me)