Having studied many Euro coupes imported to the US and Canada and owning one myself I can state that there is consistent inconsistency. The US and Canadian headlight laws are virtually identical - I believed that they were drawn up at the same time with both countries working together, as far as "federalizing" a car there can be broad interpretation since there are no specifics for each and every car and what was needed depending on the year it was imported; For instance my car had rear sidelights installed but not the front reflector, and instead of replacing the front turn signal assembly with a sidelight / turn signal they drilled a hole in the housing and stuck another bulb socket in. Lastly, I'm not sure what agency would have certified the cars but I'm sure that each individual would have had their own idea of what was needed (and maybe a few palms were greased).
