Thanks again Harry. I shot you an e-mail with some additional thoughts I had. But basically, I think I have a handle on the different type of systems out there. I agree, the AutoTune with TMax seems like the best way to go, providing they perfect it. Hopefully by next Spring it will be perfected. As you've read before, I'm still a little concerned about maintaining warranty. I was hoping that HD would give the green light to the SERT and allow us to maintain all warranties. I guess I'd use SE pipes if I had to. If HD says NG, and you're on your own if you use SERT, then who needs them for this anyway. With better products and no warranty to worry about, then AutoTune and True-Duals here we come. You've been really helpful in raising my level of understanding on this subject. I'd like to thank you again and I really do appreciate it! Regards, Hoist!