Check this out guys.RAPID STRIP DISK by norton at home depot $3.97 in the grinding wheel section. Looks like a black spounge on a grinding frame. In a effort to find a better way to remove undercoat I purchased this product only to find a heat gun worked better, but, you ought to see how well it removes paint and rust.Its 10 times faster than my D/A and sandblaster. Even cleaned a brake drum. This is going to shave hours off the job. Stay away from edges and holes though as in tends to wear out faster. Lasted about 30 MIN staight use.

Im not sure if this would be a good idea to use this product on exterior sheetmetal though. Id still use the d/a, but for heavy metal its great. Just an after thought. Let me know what you think.