Driveway Ornament

a) a car that is so expensive, you wouldn't dare drive it; instead you just showcase it to the rest of the neighborhood in your driveway.

b) a car that is such a bucket, that you've given up on it, so it just sits gathering rust, vermin, and the occasional stoner.

a) My neighbor bought a new Mercedes-Benz S65 AMG last year. I swear, the car hasn't moved since he drove it home from the dealership back in May. I swear, it's become a Driveway Ornament.

b)
Guy 1: Hey, is that your Dad's Impala outside?
Guy 2: yeah, but it doesn't work anymore.
Guy 1: has it achieved Driveway Ornament status yet?
Guy 2: most definitely, bro.