The sooner you reserve, the sooner you get your car. If you don't like the terms then you can wait, but you'll get you car after the people willing to put money down right away.
It wouldn't surprise me if this becomes the norm in any 'place in line' list with high value items. Companies would love the ability to offer the chance to consumers to put a down payment for a place in line while at the same time removing any liability in case they have to break that agreement.
I'm baffled at why anyone would think it should be otherwise. Guaranteeing a strict order would be essentially impossible, and it would mean that a problem with a single unit would delay the entire group of people behind it.
Since this flexibility goes both ways (you can cancel at any time for any reason and get a refund), I don't see what's so weird or upsetting about this.