Recently installed a Cobb Turboback Exhaust i bought from the USA. What can i say? Its amazing! sounds amazing and feels amazing! Very $$ but i think its worth it. My mates told me its sound is a cross between a WRX and a Supra at low revs haha! Had a few heads turn which i love! other then that i cant wait to finish work and go for another drive!
Been 2 weeks now and driven over 1200kms so far, no problems, no cel no smoking issues. some backfiring but i guess thats normal.
Example of the exhaust when warm:
Mazdaspeed3 Cobb Turboback Exhaust Revving - YouTube
Example of the exhaust at cold start:
Mazdaspeed3 Cobb Turboback cold start - YouTube
Enjoy