That black goop is called sealcoating. It's a modified version of coal-tar emulsion. Very closely related to asphalt binder.

There's a product called "oil-flo" (can't remember if there was a "w" in that or not.) that's specifically made for getting sealcoat off things it's not supposed to be on.

You have to be very careful though......that stuff is pretty strong. I know it'll take off the sealcoat, I'd be nervous about what else it would take off!



I only know about this because I applied the crap for 3 years when I was going to school.




EDIT.......here's a link to their site http://www.titanlabs.net/oilflo.htm