I used that black on my grill last year when I got a new one and it is still going good (after a lot of use and being in the AZ sun and winter). I'll have to look to see if it is flaking off the mufflers, but the car is in the shop right now (they are keeping it overnight while waiting for a wire harness to come in). I haven't noticed it, so I would guess it isn't and I put that on in Dec 2010 or Jan 2011.

I am always amazed at the range of products companies that you would never think of (like PPG) produce for the military.