I have fiddled around with exhausts on a number of cars and it all depends on the level of muff........
My GTR had a Nismo exhaust - it was incredibly quiet, changed the muffler to a steel Luki sports muffler and it was slightly louder, ended up changing that for a straight through RPS muffler with three inch bore - now sounds beautiful.
You can get a mild steel three inch exhaust made up with a resonator in the tranny tunnel and a straight through muffler on the back for modest money - this should sound right nice!