Availability: 8 in stock
The side panel here is the GM part, numbered 26368627.
Varies by build: Lower components, black.
Covers that seal a fluid opening normally carry a single-use gasket or O-ring, and reusing the old one is the usual reason a leak comes back.
The part number is the thing to verify. Where the old part carries no legible number, a VIN and a photograph are enough for us to identify it.