hi have a couple of queries. Will a broken cooking fin on my regulator damage it or stop it working? Also does it need to be mounted to the steel subframe or is my alloy undertray ok???

Cheers

broken fin will be fine . when you remount it make sure you got a good earth to bolt it to i would of thought . i might be wrong . but its always worked for me

cheers mate problem solved.
Cheers!

bolt it BACK to the frame..... the frame acts as an extended heat sync...... heat syncs dissipate the heat generated.

anywhere is fine really although the standard place on the exhaust hanger is probably the best, my old NSR one with Tyga tail used to barely touch any metal at all and that was fine.