Well not as difficult as you would assume, the trickiest part was matching the plastic colour of the diffuser as the fins are fibreglass and are supplied in primer only but are ready to paint straight out of the box, so I had some of advice from a local body shop I have used in the past and they recommended plastic bumper paint (HALFORDS) match was perfect :thumbup: then the trick in attaching them is glue not just any glue gorilla Epoxy glue, the fins come with a recess in them like a little channel that the glue adhears to, and Bob's your uncle job done ,( no pulling off diffuser and no drilling holes BONUS), it's definitely a job that anybody can attempt. I really don't know why the diffuser didn't come with fins from the factory it looks far better with them ( in my opinion ) had a couple of opinions from some people and they thought they were factory standard so I'm happy with that . I hope this helps everyone interested, oh yes and the price is £85 for the pair (expensive for what they are) just don't tell the misses lol :beer: