Can you fully upgrade a car in Mafia 3

From this thread:

savegames are only saved locally.

X:/User/x/appdata/2kgames/mafia3

And based on this post:

Is there any chance of cloud saves being implemented anytime soon?

And this post, which pleads for the addition of cloud saves:

Please add cloud saves so the game can be continued from where you left off and played properly.

As well as this post, which acknowledges the lack of a cloud save feature:

As far as I'm aware, the game doesn't have Steam Cloud support

So for the first part of your question, yes, the game is only saved locally.

However, you are able to manually back them up this way:

Heres a method to copy the savegame to your other pc manually, in case you want that as a temporary solution.

go here C:\Users\X\AppData\Local\2K Games\Mafia III

(Replace X with your windows username)

copy the 2 folders to a usb, and bring it to your other pc and copy it back.

Go to barcleys mill area. Look for it on the map. Drive around and use your instict you'll see some enemies, kill them. Done.