I love the P13c, it's still one of the most spectacular driving cars in sim racing, but it's really only useful for hotlapping and league events. It's hands down the worst AI car I've ever used in AC. (I'm sure there are **** mod cars out there that I've never driven extensively that are worse).
It wrecks everywhere. It wrecks on Kunos tracks, it wrecks on Lilski tracks, it wrecks on Nukedrop tracks, it wrecks on everything I've ever tried. It is unusable in AI weekends. And spectacularly so - it will just explode right into the wall with no care whatsoever, and Turn 1 unfailingly retires 5 or 6 cars. I spent a few days trying every troubleshooting step possible to fix it a few years ago, to no avail. VRC and Kunos modern protos in the exact same test scenario work just fine (or, you know, as expected for AC). It was clearly not a priority (or even a concern) for the team when making it, which is fine, but a bit of a shame, as it's a top 5 car for me in the game. I just never drive it anymore because no one runs it in pub lobbies and I would prefer a short AI weekend to hotlapping 95% of the time.
Maybe a modern P13c update will finally fix it. It is otherwise still excellent. The tire warm up and temp management is significantly better than any other AC car I've driven, and the FFB feel is second to none. You can really feel the edge of the road in this car - it's remarkable.
If this is an IER return, even a minor one, I'd actually be more interested in updates to the Oreca and Dallara Corvette USCC protos. Still great cars as well, but certainly could use quite a bit of touching up. Last update for those was now 5 years ago.