Talking about quick 4 bangers..and more so..exotics..GM does make a few exotic looking cars..
For example the Vauxhall VXR220..turbo 4 banger that does 0-60 in something like 4 seconds and a top speed of like 160 mph..
thats a neat car.
Also if i remember correctly there is a opel model that is preety quick too..
GM makes some exotic looking ones, jsut not in the states