all you can do is search forums and reviews from American sites as most users on here are from Europe and the products supplied will be different
but it was me I would look for one that will also work on mains voltages so you can use it in the motel room at night or just pre cool it for the journey
Agreed and you’d be better to run a mains one off an inverter in the vehicle for that as a mains unit will be far, far more stable temperature wise.
The 12V units are pretty much all Peltier units that are not that great at cooling, okay to keep drinks a little chilled but not a lot of use for much else if you ask me and I most certainly wouldn’t rely on one for medicinal purposes.