It depends on the state they were initially registered in. They came over by either individuals who could buy them in Europe importing them in themselves, or by independent dealers in the US arranging for the purchase and shipment of the cars outside MB dealership channels. If this dealership was located in CA, or the individual was attempting to register a self-import in CA, the state would require them to retrofit the cars with bumpers and lights and smog equipment for example, and this would be true of a lot of other heavy red-tape and beaurucrat states like NY and NJ as well. If, on the other hand, they were brought into AZ or TX or any other state which had no regulations, they went on the road the way they came off the boat. My 83 280 SL was owned by a pilot who brought it over himself to AZ, so its real "Euro".