It was good while ago, but last time I bought a car I just did bank transfer. SEPA transfers are entirely free. Was kinda amazed that they just handed me keys when I showed them the receipt from my own online bank...
If you get scammed, it requires you to sue, many EU countries have very long waiting times for those, so you'll be carless and money less for a long time. Cash or crypto solves this elegantly.
Intra-bank transfers are instant, so is PayPal/Revolut/Zelle or whatever else, and many inter-bank transfers are also instant or very nearly so in the EU. None of these, except maybe cash, protect you from someone sinply not delivering the physical good (car + car keys) after the transfer completes.
From a legal standpoint, the bank transfer speed is anyway irrelevant - you first sign a sale contract that makes the car yours and the money theirs, before anything actually exchanges hands. If one party fails to deliver the money or the other fails to deliver the good, they are anyway liable. With instant transfers, the buyer is more likely to get scammed; with delayed transfers, both the buyer and the seller are equally as likely to get scammed - that is the only difference.