bum car
The empty car on a packed rush hour NYC subway train that is empty for a reason: the sweet smell of impacted fecal matter sitting in urine-drenched unwashed clothes with sweet ripe cheesy feet of the homeless person sitting in the corner.
"No no, move up. That's the bum car. "
car bum
A bum or homeless person who is fortunate enough to own a car but not much else.
We saw this car bum taking a nap in the middle of the parking lot.