+1
I don't see how this is seen as a "duplication" issue. It's a single account, you're not allowed to share the account; If you can't share the account then only a single character from the account can be logged in at a time I would expect, and therefore there is no way to RP with yourself, or any people you know, so your characters are never linked.... that also means that your vehicles should never be allowed to be out of the garage at once too (have to return Car A on Character 1 before being able to take it out on Character 2)
It's a bit naff that you can buy a car for 50 Euro, and then are completely unable to use it on other characters. What if you RP something like a crim, and then have another character for RP'ing another role in society, like a normal civ with normal businesses? What if you buy it on Character 1, and then start a fresh Character which does things you enjoy more? Should you have to donate another 50 Euros or more to have the vehicle you initially donated for in the beginning? People are donating for the vehicle, even if you wrap it inside of "this is supporting the server" the majority of people are not donating simply to support the server, but to get something instead. If you import 2 vehicles, and spend 100 Euros, you're essentially forced into using that Character forever, unless you have another 100 Euros to piss away on another character.
If you can't share vehicles across the account, then at least allow them to be transferred OOC'ly to another character on the same account as an "Export"....