A hoopty can be anything from a '78 Cadillac Brogham with the panels missing in front of the brake lights (but replaced on only one side with duct tape), to a fine purple two-year old Hyundai Elantra with three spinner hubcaps and a vanity plate that reads BBY GRL.
The term has also been used in certain circles as an insult to one's boy or girlfriend, as in scrub or hoochie mama.
2. I can see now you ain't nothin' but a hoopty.
Known for incredibly loud mufflers... if any.
"Nice hoopty... Josh"
Driver: "Hey baby, need a ride?"
Chick: "What kind of car you got?"
Driver: "It's a Ford GT"
Chick's friend: "He's lying. It's a 1986 Honda CRX. Let's take the bus instead"
Busta #2: $5 for that bucket?!