Yes, ECU is under the seat next to the battery but the connection plug/socket is under the rear seat. The cable you need is the same cable that's sold for the VolksWagen group cars or VAG compatible. And NO, they're not all the same apparently. The Arrow tune richens it up all through the revs. Some people say it gives more go. Some people say it smooths out the power delivery. ALL say it uses a lot more fuel.