Well, the guy said that the only mods that they were permitted to carry out were: weight reduction, and suspension changes and alter the ecu settings to make it more responsive (less economical i guess). I asked whether it was to be used with a filter and exhaust and he said that this particular category did not permit that - only stripping the car and suspension and ecu. He told me the car would feel more responsive and have a little more top end. Hes not an advertised garage or anything, he prepares race cars (all sorts including clio cup car, mgfs, mg V8s). So it sounds like this chip will just make my car more responsive - better midrange punch? who knows, i guess ill find out when he fits it next week!!