When I had my 500, I got a stainless steel muffler from an older Honda sport bike (1998 Interceptor). A friend of mine gave it to me. It was roughly the same size as the stock muffler but it didn't have a cat, and obviously it was designed for more flow (110 HP motorcycle). I stripped the rear rack and fenders off and took the buggy to a local SS exhaust shop. They cut the stock muffler off and welded the new muffler in, added hangers and all. They charged me $60 and it came out great. Noticeable increase in throttle response. It was well worth the upgrade.