Learn from my mistake and spend the extra cash on the APR DP. It's gauranteed to fit local RHD S3's.
Don't get me wrong, the 42DD DP is a great product. BUT! It's designed for LHD TTQ's. In our S3's, the DP once installed sits far too close to the firewall and chassis, within a couple of millimetres.
I had to have the DP modified by my local exhaust place to fit without any chance of hitting anything around it under hard acceleration.
Even though I saved a bit of cash initially, I think I spent close to $250 for my local exhaust place to modify the DP to fit properly.
This is also after spending close to 1/2 a saturday doing the install myself, only to find that the DP would not fit as well as I'd hoped.
Good luck...!
I found it well worth it, I already had an MTM exhaust and this mod completed my exhaust system.