So glad I found this post. I had a BMW M3 CSR IRL and after completing the GT5 championship in PC2 I thought YES I will do the M3 in the GT4 championship, very quickly realised I was way WAY out of my depth here... wow it was all over the place, very unpredictable and tail happy with no understeer at all... after a few hours of trying to "learn" the car it would still catch me off guard at the smallest things... I wondered if it was "just me" and I thought I would google it and found multiple page hits just like this one. I wish I had googled this before starting out the championship... I have thrown in the towel for now, but I have to say the setting that have been posted did make some difference, but I still found it a difficult car to drive. Anyway in 8 laps in the Ginetta G55 with "stable" default settings I had beaten the best time I had set after a few hours in the M3... but more importantly it was consistant... Such a shame.