Of mine the favourite was the Fiesta XR2 by a long way, I fully stripped that car down to a bare metal bodyshell, got it seem welded and then built it back up with new, upgraded, parts, built a fully balanced, lightened and flowed engine for it with high lift cams, stainless exhaust system and a couple of side draught webbers. ended up with a car that weighed about 700Kg and made 170+BHP but still looked pretty much standard... I had fun shocking drivers of "performance" cars in that little thing :)