Here's a picture of the right hand side fog insert. There`s not much room for error with the trumpet/bezel size as too big and it won`t fit, too small and they will fall through. The only ones I've found that are about the right diameter are these:
http://www.merlinmotorsport.co.uk/p1...duct_info.html
Looking for a definitive answer as i don't want to waste money or mess the insert up. As always, thanks for your time.