Hello all! I recently purchased an 06 4.2 a8L and was wondering what exactly the differance is between the 04-06 a8 exhaust and the 07-09 exhausts. I noticed that the magnaflow sight lists these differently and visually look slightly different however on others parts sites stock exhaust list 04-09 being the same. Insight would be appriciated. Most likely more questions to come! Thanks