It is, with the proviso that it's rare for Americans to order a car before it's made -- we mostly buy them "off the lot". Tesla is unusual in that regard.
As a former car salesperson, I can tell you that, in the state of Virginia, car sales contracts are not valid until the customer has physically taken possession of the vehicle. As a result, we were always very reticent to sell a car "off the truck". Customers would swear up and down that they'll definitely follow through but, most of the time, they'd just never come to pick up the vehicle and we'd be stuck trying to unwind a contract. I'm sure this is common in a lot of states.
