Are you talking about the big V3 lot under the Linq ferris wheel?? That's got a pin code to enter which will be on the screen (you may have to cancel the directions once you're there to see code). I'm not sure if the Caesars membership card will exempt you from paying, I've never tried mine as I've never been over an hour there. They have Wall Connectors but make sure it's charging before you walk away as the charger handles get dropped on the ground frequently.
There shouldn't be any ICE vehicles besides a few work trucks/vans on the South side of the lot.
If we're talking about two different locations then my bad.