One more note: If you go this route your car will think it is a SL550 If you live in a state where you get inspections like here in Texas, they hook up to the OBDII port. When they do this they will get a suprise. You could tell them it is a SL550 with the Crossfire body kit Or you could could wire in a couple of hidden switches that make it impossible for them to read from the OBDII port. If they can't get a read they are required to input the car's VIN manually into their system. So you should still pass inspection.