I bought my AP down pipes from Vishnu. AP's website is http://www.agency-power.com/
. Sorry, I only drove to/from work in the city. Not much to base comments on about it. They do tie in well securely as they have added tabs, I'm told by my mechanic.
Shiv tuned since Nov 2006, Quaife Feb 2007, Helix FMIC, Agency Power downpipes, M3 suspension parts, KW V3 w/Swift springs, Dinan intake, HID fogs and 235/265 tires