in quebec, if you have an exhaust that is louder than stock or does not have the same design characteristics as stock then you can get a ticket. unfortunately its up to you to prove in court that your aftermarket/non-oem exhaust has the same design as the oem one.
over here, most people who get tickets like that just pay it off and lean to keep the clutch in and roll past the cop cars next time you see them on the street.
by the way, i know from personally experience that the AA exhaust is pretty loud and boomy at low rpms, if you have the full version with the x-pipe, the sound gets even worse. i am not surprised that you got pulled over.
if you had a quieter exhaust like a remus sport or eisenmann sport, you'd probably have gotten away with it.
a cop pulled me over in downtown montreal bout 2 yrs ago and gave me a warning for my magnaflow exhaust and a $150 ticket for my 50% tints. i have since changed to the bastuck exhaust and removed my front tints. havent been hassled by a cop ever since. technically my bastuck exhaust is still NOT-legal but because its so much quieter, i think it attracts a lot less attention.
Current: 2013 F10 M5 & 2013 GLK350
997.1 GT3RS (gone)
2009 WRX STI (gone)
e92 M3 (gone)