The specific problem with those paint jobs was water base paint systems. The car companies were experimenting with water base paints in an attempt to meet government VOC laws. They used water basecoats and then topcoated with urethane clear coats. The urethane clear did not fully adhere to the base and you guys have seen the end result, in some cases the basecoat would de laminate from the factory sealer. I painted a lot of "peelers" during the early 90s as well, GM seemed to have the most problems.
Our best results were with razor blade scrapers, it takes a little practice but in most cases the clear would come off rather quickly. We would sand the base with 320 on an orbital sander. The base will ball up and clog the paper so you will need to change your paper out regularly. Then wipe down with a good wax/grease remover and seal.
