Who knows about CUIT or working with a provisional work permit while waiting for the DNI? I did a search and found a broken link to the AFIP website.
If I have to sort through excesses of legal mumbo jumbo on the AR official pages, I will... but I would rather take the path of least resistance on this one with your help ;-)
you need to get a CID if you hv no residency as yet to buy a car.