The other posibility would be that the car is German in origin. It is pretty common here to buy and import used German sold cars.
One other wrinkle...the car was badged 200sx not 180sx. It looked other wise stock and it was newer than 91. This is where the German part comes in to play, I am 99.999% percent sure that there were German sold HB's with sr20det's. I know I have seen at least one, also badged 200sx.
IIRC the HB, (aka 180sx aka 200sx) was produced untill 1996 in Japan, though I have no idea what it's production run was in the various parts of europe. Think if I see one again I will have to have them pop the hood, and get an answer once and for all.
But I still have yet to see a coupe or s14 here <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/sad.gif" border="0" valign="absmiddle" alt='
'>