Well first I wouldn't say a 328i is really a luxury sedan, but, to your point, it is a decent handling sedan. The real issue is that the Vauxhall can't as readily apply it's power. Part of that is the problem with the FWD and part if that is the laggy turbo. The car looks nice, but I think it would be way better and have great tuning potential if it were AWD.
135i, SGM, Coral, Sport Package, Auto, Premium Hifi, USB/ipod, Forgestar F14s, PPK Stage II