The actual purchase process might dox either the winner or the owner of Freebitco.in.

It's actually quite easy to buy a car through an intermediatory. That's what
https://www.moonassets.io/supercars are doing for example. They don't actually sell cars they just handle the Bitcoin to fiat conversion.
wouldn't the winner ID still be needed to buy and register the car?
or the intermediatory would use its company name to finalize the transaction and transfer the ownership?
either way, there is no way a winner can claim this car without providing ID, am I right?
so... the easiest and safest way for both the winner and wetsuit would be thru BTC reward