I have had this filter for 6 months now, 5 months on the UK EP3 and now on my DC5. I bought it mainly for the looks but I love the sound it makes in Vtec, the car just screams. As for power increase, well i have not been on a RR so I don't know what power increase if any but my guess is that there must be a couple of bhp there somewhere, the sound makes you think its quicker but I can't prove it. Like I said earlier I got it for the looks and I think it looks the dogs when you open the bonnet. Will post pictures as soon as I can