with mr.clean magic sponge...
Last resort, if the oil and tar won't come off with regular cleaning brush, you can use a pressure washer surface cleaner from bestcargurus along with your pressure washer, that will surely do the job.
blacktop tar cement pavement
To take tar off a jute rug, first take it outside to shake off loose particles. Dampen a clean cloth with club soda and rub affected area to gently wipe off tar.
use somegoof-off or paint thinner or gasoline
cracking
Kerosene works very well and will not harm the windshield. Brush it on and let sit for a minute, then wipe the tar off. Wash thoroughly with alcohol.
The only thing I have ever had luck getting old hard tar off of anything is gasoline. I wouldn't recommend using it in the house though unless you have alot of ventilation and you clean the gas off the walls with bleach or some other cleaning agent.
powerwashing
I Have always used WD-40 to get Tar off my cars. It just wipes off with the WD-40 then I clean the WD-40 off with dawn dish soap, and then apply more wax to the area. Hope this helps you out.
the best way to get paint off your driveway would be mineral turpentine.
Any petroleum based product should work. WD-40 is one.