Oh god, don't get me started on asset forfeiture.
The cops can take your stuff, as long as the follow the rules. Which consist of a) is it possible your stuff could be in some way used in a crime and b) do they want to take it.
Since cash and cars can both potentially be used for crime, you can get it confiscated for just having it. Even if you have a legitimate reason for having it.
Then once this seizure has happened (no need for any judicial overview) then you have to take them to court (with all the speed and expense that entails) to get your car/cash back. God help you if you're not the whitest of white, because then you're fucked in the courts.
As for the *intent* of it, well, you'll notice that those people with shit loads of illegal cash also turn out to have veeeeery good lawyers. So they are actually quite good at getting stuff back, along with filing harassment suits etc.