First, I'd say any difference in value a couple of years down the line between the old plate and the new will be negligible. Maybe if there was going to be a facelift, or a worthwhile upgrade in specs. It really wouldn't be a factor for me.

But depending on the specifics of the deal, I think you may be looking at this the wrong way round. My understanding is that people use places like Car Wow to get a better deal on price. If this is why you are, don't you think one of the reasons for the good price is because the new registration number is imminent?. So rather than feeling you should be entitled to an extra discount for going with the 2024 plate, maybe you should be asking how much more you'd be paying to go with the new plate?

Dacia aren't known for being generous with discounts, the rational being that they are already cheap (if maybe not quite as much as they once were).