Car: 2007 CTR, Alabaster Silver
Join Date: 11th October 2007
Location: East Midlands
Thanked 55 Times in 54 Posts
The comments here regarding insurance are generally correct. You really should declare it. My premium went up by about £20 for a non-standard exhaust.
Regarding noise, the only way to tell is to ask someone to drive you around for a bit. Personally, I was worried that it would be too loud before I bought the Milltek, but the sound is just perfect to me, even at Motorway cruising speed. I really don't think that it's too loud - it's certainly nowhere near as loud as I had anticipated.
Performance gains aren't really noticeable.