Alex, E&G exhaust tips (90 new, probably 40-50 if you get from a forum member) & then drill a small hole into each of your mufflers & take out some of the fiberglass out... this will give you a deeper grumble & a good looking set of tips. This is a very simple "do it yourself". one of the old threads:
http://www.cadillacforums.com/forums...st-system.html (Whos gutted the stock exhaust system...)
or you can find a

in your area & buy his old stock exhaust off of him. Bolt it right onto your car in place of your stock system. boom mission accomplished. Stock V exhaust will run you anywhere from $0-100 normally. Install is a do it yourself, or you can have a shop do it (probably charge you around 50 bucks)
If its sound you're after, get an intake... Volant for the most power on a 3.6L & K&N for the most power on a 3.2L. The K&N is the louder of the 2 exhausts (and theres only a 5rwhp difference between the two) so ultimately you're after sound, then go with the K&N. I wanted power & sound, so i got the volant & cut a hole in the front of it. cost 200+ -- then you'll need tips.. E&G is the way to go (40-90 bucks)
But if you're gonna spend that much, might as well go ahead and get a set of magnaflow muffs & have your exhaust shop weld them on for you... around a 300-400 job. Not really much of a performance gain, but will give you the sound & look you're going for. (If you want power out of this deal, change out the resonator for an x-pipe).
you got a lot of options, its up to you...and don't knock that gutted stock intake idea.