Sounds Great... Cammed sound with just a tune... Genius.... I don't know if I have missed anything but is there any power loss with this tune to make the lopey sound? If so that could be a deal breaker with many people.
Did you check all the bolts on your shifter? is there any vibration coming through the shifter? My 04 made a similar sound and it also had the 3650 trany. Not to freak you out, but mine was bad syncro's.
No leaks when completely closed. QTP make a good quality piece. There are a couple of other brands of cut outs that are out there. I went with QTP because they offer the low profile oval cut outs for lowered cars. They sound great but a lot of power loss down low with them. Up top it is a monster.