Actually if the fee is just a filter, they could refund your money if you buy any car in the next say 6 months. That way it's less of an obstacle for potential buyers but still filters out non-buyers.
If I'm trying to decide whether to buy a Maserati or a Tesla, and you tell me I need to pay you $300 for the Tesla just to test drive it, I can tell you that I'm buying the Maserati, since they've already figured out that I'm a potential buyer.
Tesla is smart to size up the people that walk into their stores so that they don't offend the ones that actually can buy their cars. If they offend non-customers, so be it.
If you give similar answers to the Maserati sales rep, they will also charge you a fee for test-driving, or maybe not even let you test-drive.
Like I said, any high-end car sales rep is trained to quickly profile potential buyers. They judge everything from your looks to your body language and profession. When you're talking about really expensive cars, it's better to err on the side of caution and lose a few potential sales than let just any loser off the street test-drive one.
I had a friend back in college whose dad was the owner of a local Mercedes dealer. After interning there for a summer, he cryptically told me that he "cracked the code." From there on, his favorite hobby became dressing up in nice suits, walking into a high-end car dealership, and convincing (with 95% success) the sales rep to let him drive one of their cars. I accompanied him for one of his trips and got to test-drive for free a Lexus convertible, a Ferrari, and a Nissan 350Z back when it was new.
If you're really deciding between a Maserati and a Tesla, I'd be willing to bet that Tesla isn't actually going to charge you $300 to drive one.
If you walked off the street into a Maserati dealership dressed like a hacker, refused to provide any information qualifying yourself as a prospect, and demanded a test drive, you might not be allowed to drive one at all.
Of course, if you wanted a Maserati, you could probably have one next week. Tesla is back-ordered to forever. So whatever they're doing seems to be working OK.
I've paid $3K to rent an Audi R8 for the weekend. I currently have a Model S reservation. I'm cool with paying $300 to see if I want to spend $80K on a car (0.00375% of the value of the vehicle).
The Roadsters sold for that much, but are no longer on sale. The Model S price is a little over half that. You can get above $100K with the right combination of options, but most sales probably won't be for anywhere near that.
