What on earth could make this chavvy? Nobody from outside can tell its there and nobody from inside can either unless u tell them. It cancels out noise that u don't want in the cabin and enhances what u do, it's not like a speaker that plays a fake engine noise. I don't see this as a negative, and besides, if u open the windows u can hear the "real" noise.
Also benjic2 how did u even find this thing, as I can't seem to find any information on this at all. Also what difference does it make to the sound in the car?