[svandamme]

Well maybe not single phone transation
but back when i lived in holland , it really was close to being that simple

get loan, get cash in your account
go to seller , take posession of keys and papers
call bank, initiate transfer of the funds with a speed wire transfer
Seller checks his account, sees the money minutes later
do the transfer of the title
call your insurer, and you are good to go

The key to all this was that number plates stay with the vehicle.. So no need to wait for plates to be made and sent to you..

So not a single call, but you could get it sorted in half an hour really.. And the porcess streamlined to more online since I lived there...