Can't you fit the ST170 airbox bits to a normal Focus? Heard of a couple of people doing that and said it seemed to help. Though I suppose some of it can be pricey second hand perhaps.

I'm sure a 15bhp gain is going to be noticeable on a car of that type. A 15bhp gain on a 400bhp car might be far harder to spot, but gaining 15bhp when you only have 130bhp to start with is definitely going to be something you'd notice in my opinion.

Neil, are your exploits from Anglesey going to be in the mag? I'm afraid I was there and did spot what happened