If the amount you deposit affects your spot on the list than that is not a particularly honest dealer. I wouldn't want to do business with them.
I put down my deposit a few months ago. When I did so, I was told that I would be able to spec out the car how I like once they got their allotments. I was also told that I can get a full deposit refund at any point, even when the car comes in to the dealer. They said that they would have NO PROBLEM getting rid of the car if I decided it wasn't for me.