I do not have any info on Alfa Romeo sales in USA actually... but I guess that except for the small spiders (and maybe the Alfetta), they are not very common.
Alfa pulled out of the market in the 70's mainly due to emissions' regulations.
Since then I remember only the 75 'Milano' (V6 2.5, later 3.0) in the '80s and the Alfa 164 (V6 3.0) until the middle '90s.
I believe they were sold through the Chrysler dealer network.
As appassionato says, this is an US-spec model.
Alfa Romeo leaved the North American market in 1993. It was an abrupt decision because, when the first press photos of the GTV & Spider were published in the european motoring press in early 1994, one of the cars - I believe it was a GTV - was slightly different. It had no "blinkers" but had orange and red side lights instead... just like a US-spec model ! Which meant the GTV & Spider were ready for export well before the decision to pull out of the US market happened.
Sadly the rear is what we only see of this car, the closest view we have of it is the one in the main picture, we can also see it several times in the far.