Around here, "hoopty" carries two distinct definitions. The Urban Dictionary "Hoopty = Piece of junk" definition Jeri linked to is, perhaps, the term's original meaning and is still in use. But it has also come to mean a customized full-sized American-made car of model years roughly between the late 1960s and early 1990s. Customization is primarily cosmetic in nature (fancy wheels, paint jobs, and interior work) instead of performance related. That's not to say a well-maintained 1969 Chevy Caprice hoopty doesn't run well, but its owner's main goal is to have it be visually impressive, not to see how fast he can make it do a quarter-mile.