'Rules of Engagement' Star -- I Got a New Cadillac!

"Rules of Enagagement" star Adhir Kalyan just got a new lawn ornament ... an upside down Cadillac.

Kalyan and GF Emily Wilson (from "General Hospital") were minding their own business at around midnight ... when they heard the thunderous crash. They went outside to investigate and saw the inverted Caddy and called the cops.

Law enforcement sources tell us 2 guys were in the Caddy when it crashed and managed to crawl out.

Now get this ... as they fled, one of them told a witness, "You never saw us here."

Definitely not your grandpa's Caddy.