i just recently got the guy that works on my car to adjust this tiny screw and my steering is fine now, he got at it by taking off the front driver side wheel,the wee rusty thing ye can see in the pics is the plate about the size of the bottom of a cigarette packet,when the plate is removed theres a circuit board and on that theres a small silver square and a tiny screw in the centre of that silver square,the guy turned the screw 1 way and the steering got worse but when he turned it the other way the steering is now near perfect,i shouldve took pics while he was doing it, these 2 pics i took with the wheel still on 5 mins ago,i hope this helps,both t20 screws broke when trying to remove them,he just stuck the plate back on with some kind of adhesive. BIG THANK YOU TO MATT66604,ye saved me a good few quid,although i had already ordered and paid for a used ecu unit but still thanks to this thread im still quids in