What exactly does the 2001 Cadillac Deville exhaust consist of? I haven't taken the time to look under the car yet to see, but it sounds extremely quite for duals. And if I were to add some sort of exhaust modifications what would you recommend?

quiet***

It is a single that splits to duals near the rear wheels. The best system for it would be the Corsa cat-back. I have that system on my 2000 STS, and it sounds awesome!