remove everything on the interior, as far as im concerned all that needs to be in there is the pedals steering wheel, shifter, seat, shift light, ecu and a handle on the driver side door so you can get out. You do not need to be running the huge gas tank for autocross. Cut out the entire floor and install a 3 gallon fuel tank. You dont need the tail lights either. Ditch the bumper supports and all the associated mouting stuff since you are running a cage (i assume this is a race only car). get lexan windows. ditch side mirors. remove sunroof and replace with sheet metal. remove windshield wipers and motors.