I used to work as a carpenter for the housing maintance section on a military base for several years. The guys who had to clean the oil spots in the driveways used to spend hours and all kinds of cleaning stuff to get them up. One day a colonel's move out failed inspection because of driveway oil spots and the new colonel was parked out front with a moving van and crew that couldn't unload until the house passed inspection. It suddenly became a huge emergency and all kinds of officers and cleaner crew and anyone else nearby was standing around being part of a big clusterf@ck. I was working next door and after a half hour I walked over, poured about a cup full of laquer thinner on the spots and brushed with a stiff scrub brush for a couple minutes and then wiped it up with a handful of rags. I did it twice once immediatly after another and waited about 3 minutes for it dry. Everyone's jaw dropped when the spots disappeared . The largest one was about a foot and a half in diameter and old.From that day on thats how all the driveway oil spots were cleaned on that base.
Try it.
It works with very little effort or cost.
But really you should just buy a house . Nobody says a thing about whats in my driveway. When I'm out working on my cars in the driveway , my neighbors come over and watch. It's great fun.