Let us take care of the messy stuff. The interior of this awesome bag is Vinyl-Coated Polyester, which is much easier to clean than your vehicle interior. Seriously. It's a great place to store your bottles of engine fluids and other chemicals.
The oil bag measures 12"x12"x5", and the front has 550 paracord for some extra storage.
It also comes with a ground cloth (no eyelets.) Pretty handy to throw on the ground before you crawl under your truck when you just happened to stop over a mud puddle.