I found this picture of the infamous 5th splash shield on a Camaro site. My repro shield kit has one of the these pieces but I have read somewhere, I can't remember if it was a Firebird or Camaro site, that showed the two-holed mounting brackets for both sides.

Anybody seen them installed on both fenders?

No, I believe they only used it on the drivers side to protect the fuse box bulkhead connector.

Makes sense. Maybe the guy just happened to have two brackets and one was bent opposite to fit the pass side.

This is related, I believe...

The splash shield on the RH side of the radiator support has a 1" hole and slit. It's as though a hose or line is supposed to go there. However, it's too low to accommodate the AC hoses. Anybody know this one?