AFAIK, no production
vehicle supports NEMA 14-50 directly; they all require an EVSE (such as Tesla's Mobile Connector) to plug into a wall outlet of any sort. At the moment, most non-Tesla vehicles come with EVSEs that have NEMA 5-15 plugs hard-wired to them, so they can be used only on 120v outlets. (Chevy's current EVSE is actually capable of handling 240v, but that requires a very non-standard adapter. My understanding is that most other EVSEs provided with cars contain at least some internal wiring or circuitry that's incapable of handling 240v.) A few automakers are beginning to provide 240v-capable EVSEs with at least some of their cars, but in terms of automakers or models, they're still in the minority, the last I heard. I saw an article comparing the EVSEs that come with production cars a while ago, but I can't seem to track it down now.
Of course, any given EV owner might have purchased a third-party 240v EVSE with a NEMA 14-50 plug, but you can't count on this being the case, if the point is to provide charging to guests. For that, a J1772 EVSE is the best choice, although a Tesla EVSE, such as the Mobile Connector that comes with the car or the $500 Wall Connector, along with a
JDapter or something similar would also work.
Overall, it's hard to say what will work best for
@pfalor, since there are too many unknown variables, like why a second EVSE is desired in the first place, what other car(s) might be charging, what third-party EVSE(s) the owner(s) of those car(s) might have, whether increased Tesla charging speed might be desired, what sort of budget is available for this second EVSE, etc.
