It has been a little over 7 years since I started this project. Today I undercoated, and then painted the underside of the body with 3M 08883 rubberized undercoating and single stage black paint. It took seven and a half cans of the undercoating to completely cover the bottom of the car with two coats. After the undercoating dried for three or four hours, I sprayed painted it.

So here is what has been done on the underside of the car.
1. Sandblasted
2. Acid washed
3. Painted with POR15 rust protection paint
4. Undercoated
5. Painted with single stage paint

The bottom of this car should remain un-phased by anything that can be thrown at it. The pictures below show the underside of the car painted with POR 15, then undercoated, and finally painted with single stage paint.