The cars you describe might be at the dealership, but they’ll be in the showroom, behind the big glass walls. It’s not that they can’t get them out for a test drive, but it’s a big production, and will def give them time to check you out before you get the keys. And at that level the salesman is going along.
When the Tesla R was brand new I went to check them out. Test drive was available, but the salesman did the driving. Honestly, I was pretty accustomed to high acceleration as my Dad is a car guy. 12-cylinder Jag, Mitsubishi 3000, that sort of lower level vroom cars. But when we got into the Tesla the salesman asked me to turn on the stereo, then he hit the accelerator. I couldn’t lift my head off the headrest, much less reach the stereo buttons. I’m certain I would have cracked it if I’d done the first drive on my own.
A key to all this is what you drive up in. They knew my Oldsmobile - though a “luxury” car - was not in the same category. He probably only took me for the ride because I was young and cute at the time.