Nothing that I've seen; I'm not even sure it's really going to happen. Tesla doesn't have a whole lot to offer that Apple/Google/Samsung etc. don't already do. You don't need car controls or X baked into the OS.
Really, a Tesla phone would mainly appeal to Elon Musk worshippers... you know, the sort who bought the Not-A-Flamethrower and wireless phone charger, the cryptobros, the ones who would probably go to a SpaceX colony on Mars just because Musk made it, that sort of thing.
I'm reminded of Red's one and only phone. People were convinced this would be the ultimate camera phone, that the 3D display would be something special... and it basically turned out to be an ordinary phone (mediocre, even) with a 3D gimmick and a ridiculous price tag. A Tesla phone probably wouldn't blow away an iPhone or Galaxy S23 Ultra; at best, it'd offer an interesting twist. That and the yearly smartphone update cycle would be hard for a company notorious for years-long delays and sticking to the same formula past its sell-by date.