Was overtaken by a Maserati Quattroporte today, it sounded absolutely awesome as the driver was really ragging it. I do like to hear a nice engine driven on the limit.
The sounds that really sticks for me was pretty much any group B rally car. I was at Cirencester in 1986 and remember the MG 6R4 as the stand out noise. There is also something about an Audi Sport Quattro as well from that era.