brickboard,

my 89 240 dl is starting to rust down by the rocker panels under the plastic molding that runs between the the wheel wells. mostly the rust is at the ends where the wheel wells are.

i have used a 3m undercoating spray in the past that is really nice for under the car. it is kind of a tar and will most likely disolve with gasoline.

any advice on what paint i should use? i will probably do the whole strip and possibly the under lips of my wheel wells.

i have considered 3 products: por 15 with a brush, 3m undercoat spray, and good old spray rustoleum. any advice? thanks.