You see all kinds of interesting stuff at General Motors’ Milford Proving Grounds. Things like Corvettes, and also Camaros. But one of our intrepid spy photographer friends caught a very unusual Camaro testing out there recently—both because of its age, and what’s apparently under the skin.

Yes, that’s very clearly a third-generation Chevrolet Camaro, the one that ran from 1982 to 1992. It’s a nice yellow color, too, and appears to be in shape.

Yet here’s what our spy shooter had to say about the car, which packs manufacturer license plates:

But this is no ordinary Camaro as witnessed by the Manufacturer plate and a sticker on the windshield that allows it access to the Milford proving grounds.

We followed the Camaro closely for some time, counted the shift pattern and noticed that it was shifting using a six-speed manual transmission. The engine, meanwhile, sounds like a GM’s current Small Block V8. This Camaro prototype also has a roll cage, twin dual exhaust tips, a raised hood hood, and GM Performance Parts badges on the sides and back.

This would not be the first time GM used a third-gen Camaro for testing purposes. Back in 2014, it tested a third-generation Camaro alongside a camouflaged sixth-generation Camaro as a sort of ultra-camouflage.

A six-speed ’80s Camaro with a modern V8 (the LT1, I’m guessing?), a roll cage and some other performance goodies? I’m not even a huge F-body fan, but I’d sign up for this thing.

Cool as all that is, we don’t know what this car means. It could be a testbed for some new factory performance parts; it could be a powertrain mule of some sort, perhaps even for a new Camaro or a similar vehicle. We reached out to GM to clarify, and on the off-chance they get back with us, we’ll update.

If you have any insights, .

Update: Here’s a tip from a reader I find pretty plausible:

I do actually know what this car is as I might have driven it at one point. I was a co-op for GM during college and one term was with GMPP (I think its technically Chevy Performance now, but w/e). This is one of the mules that they use for crate engine development. The GM plug-and-play crate drivetrain package requires quite a bit of work simplifying harnesses and correcting calibration for the vehicles missing pretty much everything you have in a modern car.[During my time] the fleet had like 2 of these, one had an LSX 454 in it, the other one maybe a standard LSX. There was a mid 90s Camaro with an LS9 and ladder bars, a Trailblazer SS that had a CARB legal LS7 crate motor, a gen 1 CTS-V with an LS376/525 (best crate motor ever), a GTO that still had some holden badges on the sill plates that was used for transmission calibration, and a Tahoe with an extended and reinforced front end that housed one of the 3 Cadillac 16 engines that they made (and still worked). I’m sure they’ve been rotated around now since that was before they started doing the GenV LT crate engines.And yes, you would get funny looks driving around the proving grounds in something 30 years out of date.

More pics below: