i had a powerflow system on my 147 with a 5x3 slash cut oval exit which filled the gap perfectly and looked mean too. sound wise i didnt want too loud so powerflow fitted the largest silencer that would fit and it was great IMO.
not the best clip in the world, lots of whistling due to being in a very narrow lane but gets the exhaust sound across i think
ps - you may have seen / heard it around nuneaton last year as i spent a lot of time there! the A444 is great fun
