Classic Saab 9-3/GM900 (1994 - 2002)/Conv ( -2003)
Hi, had the 9-3 about six months now and although I never notice any "smoke" when driving, occasionally (about six times in 6 months) I've noticed there is a patch of soot on the drive under where the tailpipe was parked.
Is this a problem and if so what would be the cause?