I've got a 940 estate. I find it doesn't roll about on corners, although I expected it too. The suspension is pretty firm on mine (but bog standard as far as I know). The only thing I find is that taking bends a bit quicker than is healthy can lead to a tiny amount of understeer, but then it is a big heavy car and I've experienced the same understeer (or worse) on my much lighter and newer Vectra that I had previously. Also, on mine there is no mirror on the driver's sun visor. Perhaps on your a previous owner might have put a passenger's one on the driver's side for some reason?