I have a used limited slip differential that fits vauxhall/opel corsa f10,f13,and f15 ger box. I bought i used and i drove on it for a week and took it back out. since i wife started to driving my car...

By adding some discrete drag reducing under body work, I have calculated it would be possible to reduce the car's drag enough to reduce fuel consumption by about 10% This also turns a 100mph corsa into a 105mph Corsa :) I was thinking of making a prototype to test my calculations, if it does...