These people have got the right product for removing oil from driveways. I've tried it and it works. I tried alsorts of stuff before like cola, clothes washing liquid and wd40 made it worse. I also discoverd that they are now doing a discount voucher thing if you look on youtube. That's why I put that link in. The link to their shoop is
http://www.serpro.eu/...in-Removal-Kits.html. You can buy just the liquid if you've already got the other bits and pieces. I found it useful to watch the video before I used it, it was suggested buy the guy on the phone, he was really helpful.