so it happens that i stumbled upon a series of youtube videos detailing the kreissieg exhaust setup for the z4m's that recently became available. all
17 youtube videos posted by kreissieg themselves:
http://www.youtube.com/view_play_lis...6805D169AABE27
and of course, the rather princely sum being asked:
http://kreissieg.ocnk.net/product/402