So I've been thinking about what [second-hand] car I want to change to in a year or two and I've reached the conclusion that for the kind of money I'd be looking at (maybe 30k give or take) I'm not going to find a lot that's less than 4 years old and gives me much of an upgrade from my existing 3.0R in terms of interior, exterior design, handling or performance. A late model VW R36 is probably as close as I'd come but it's only a marginal improvement anyway.
Conclusion: I'm probably going to be keeping this car for a while.
Solution: mod this fucker
Restrictions: I can't supercharge/turbocharge the car as it creates a problem with people on their P's not being able to drive it (or removes the problem, depending on whose perspective you look at it from). I reserve the right to reneg on this decision at a random point in time.
Current setup: MY05 3.0R AUTO with STI quads, dixcel pads & rotors, tuned for 98RON and other minor changes.
Looking for:
* power increase especially in low & mid rev bands
* maintain some backpressure in exhaust to maintain low-end torque
* no drone
* slight sound increase OK but nothing significant
* minimal loss of ground clearance due to exhaust components
Considering:
* Raptor headers
* Replacement of front two cats with high flow (200/100cell) versions (one per bank) and join to centre pipe with new 2-1 collector [advice from Robbks]
* Removal of third cat in 2-1 pipe [advice from Robbks]
* Maintaining existing mufflers (STI quads)
Unsure about:
* Whether to keep centre pipe stock or not
* Whether a change to the resonator required to keep noise under control
Sure about: the fact that no matter what I do, I'll still want more.
LUVIT, BJ, bates91 and probably others are happy with the performance gains given by new headers combined with other various exhaust mods.
I'd appreciate any feedback from anyone who has gone down this path and can suggest what I should or shouldn't be considering. I'm hoping at the end of the process I can come up with the 'ideal' change package which others with the H6 can refer to when they have the desire for more power but don't want to go down the charged route.

