Not "everyone" does it; some dealers do, some don't. I ordered a Pcar last May and negotiated a nearly 8% discount off of MSRP. The car was delayed, and delayed , and delayed again. When I finally took delivery of the vehicle this past January the selling price, as well as interest rates, had both gone up dramatically. At best the car was being sold at MSRP now...... at worst some dealers were charging up to a $20k "market adjustment" on whatever stock they could get their hands on. In my state the dealer could have simply tried to pass that adjustment on to me with little to no recourse outside of returning my deposit. He held firm at the stated price that I negotiated back in May. The same deal that was consummated with a handshake and a $1k deposit for a mid-six figure vehicle. That, to me, is a sign of integrity....
Now... on the other hand, I entered into a written agreement in early/mid July for an Emira at a local dealer that purportedly sold a fair share of Evoras. At the time I was told I was "in the mid-20's" in terms of deposits and I was assured that I would "very likely" be able to place an order sometime in the first qtr. of '22 with delivery by year's end. When I spoke to this dealer in late December he told me he'd be in touch sometime in January to get my final build and enter it into the factory. It's now March and calls are unreturned, emails requesting transparency in regards to allotment are ignored and I haven't a clue as to where I NOW stand in their queue but I've resolved myself to the fact that an FE isn't in my future so I'll wait until the base orders open up. Stories abound as to Lotus dealers that made promises of delivery at MSRP and are now reneging on same and others that are offering up FE builds that presumably should have gone to early depositors for an ADM. That, to me, is the opposite of integrity.
IMHO the UK example of deposits was far superior as it appears to simply be a matter of WHEN the order was inputted into their system as opposed to a litany of factors that appear to be a tad "murky"...