I have just tried a K&N 57i induction kit. Fitted well, good gains in throttle response and above 5000rpm in performance. However far too noisy!!
So decided to return to the 'standard' K&N panel but with the 'in wing' inlet modified. This basically envolves removing the existing resonator/ water trap and replacing with a suitable piece of tube and an 90deg. elbow. This then provides genuine cool air (depending on where you live!) and not underbonnet warm/hot air and removes the rather restrictive original setup. This gives performance IMHO, similar to the induction kit and only a moderate rise in induction noise.

Anyone else tried this or perhaps developed it futher?

 

There have been quite a few threads on this before. I think the only concern some had was water ingestion or water contamination of the MAF sensor being too much of a risk for most compared with the small gains. I too had a 57i and went to an ITG panel filter for the same reasons. I absolutely rely on the MAF sensor as I run quite high boost so I have not fiddled with the resonator.