....Hi Joe,
Millteks are officially guaranteed for life for their first owner - But that means that they are a product unofficially guaranteed to last at least as long as a car! So no worries about them being second-hand! All stainless steel and handmade.
Milltek Quads won't deliver any more bhp gain than the Milltek Twins. Without a remap you'll only see about +5 bhp max and it also depends if you have a Cat-back or Hi-Flow+Downpipe at the engine end.
Resonated is slightly quieter than Non-Resonated (which is not at all boy-racer). You can easily swop out the middle box to go from Res to Non-Res if you want later.
What do you mean when you say:
"I know it's not a full exhaust but can I add the rest at a later date?" - It must be a full system to be of any benefit whatsoever, otherwise it's only cosmetic and also could give you back pressure problems etc.
Turbo-back = Hi-flow+Downpipe = more efficiency and power, probably +15 bhp if remapped. +Sharper throttle response either way.
IF you go for the quads, I'll very soon have my Abt rear for sale - It would need repainting to match your body colour (no problem to a pro). I'm not going to get greedy over the price.
If you want to ask Milltek anything - 01332 227 280



Top pipe in pic is Turbo-back and lower is Cat-back (I swopped)....
