San Clemente Secret BBQ spot?
Rick's Secret Spot is what you're talking about.
The portions are huge, the sauce is good.
The blueberry macadamia cobbler is incredible.
My office gets lunch takeout from there once in a while. Tasty food for sure.
It's hard to find but I'll give it a stab:
exit Pico from the 5 fwy and go east about a mile.
Turn right on Calle Amanacer
Left on Calle Sombra.
It dead ends into a little office complex (veer left).
Rick's is back there. Check hours though, because it's in such a strange location.
Here's a review I found on them: