I hear chassis saver is pretty good paint. It must be good as there is no solvent known to man that will take it off your skin. You might as well just take an orbital sander and sand it off up front since you pretty much need a new layer of skin before the overspray comes off your body.
I'm sure there are other very good sealing paints in black that will weather the elements.
As per other discussions recently, how well you prep the metal before hand is very important. If you can't get to it very well to sand or powerwash, then a brushing with a wire brush to get most of the old off and then recoating with black undercoating or bed liner might be the best. That is pretty easy to touch up with a rattle can as it needs it down the road.
