In my experience from a number of different EU locations, none have pick your own vehicle. I tend to get what i booked, plus any upgrade if available. Upgrades are not guaranteed, even reservations that are guaranteed are not well… guaranteed.
i normally get notification of my specific vehicle a few hours before pickup. I’m sure i could complain and get something different, but they may not have stock and TBH, i just want my car (for work) and go.
YMMV….
if you want something specific, try and book it and hope they have something like that when you get there.