Was great to see this in the flesh mate, was a cracking looking car. I have the ultras on mine and they work a treat, used the magnecors on a previous car and they were spot on but one of Phils has broken on him. If you think its misfiring check for water sitting on the spark plugs, has happened to me a few times, if you pull the leads out they maybe a little wet but also get a torch and look down onto the top of the spark. Hope its a simple fix anyway mate