heres my poor man's exhaust mod:
Sorry for the crappy pic. There is an internal flange so 3-4 washers should allow for the muffler to be fully detached, leaving about 3mm of space. The exhaust becomes loud at 2.5k-3k+ rpms and there is no drone except for when im cruisin at 70mph, but the drone goes away when im going faster than 70mph.