r911

very little resonance - unhearable with windows rolled up; minor with them down (on a cow horn style dual out)

the Monty is the class act for mufflers in most ways; you might also want to search on the term mb911 at Pelican for a well-regarded muffler that is now about 1/2 the price of the Monty -- they went up a lot -- or the US Dollar went down a lot...