how reliable were the 86-91 560SEC's? just lookin around doin some research on them....so at 20 years old and with possible 80-90K on it would i get another 100K out of it? what r common problems? what breaks easily (besides AC cause thats just a given) what is the maintence schedule like? how difficult is the stuff to fix on it? (i know i know...its a benz...its gonna be a pain in the *** and theres gonna be a need for like 40 special tools for fixing anything) is there any aftermarket performance support? are the parts diffcult to find? im not even gonna ask about expense cause god knows itll be an arm and a leg... thanks for anything u can give guys!