actually US spec refers to the sidemarkers in general.   north america was
the only continent that got these dumb rectangular sidemarkers.    look at
european vanagons...dont have rear sidemarkers.    at any rate, if you have the
proper color bulbs in the sidemarkers, then they are 100% legal for state
inspection.
look at the mk3 golf GTI, Jetta GT, GLX, etc..came factory w/ smoked rear
lenses.   as long as the bulbs show the proper color, it will pass state
inspection.
use red bulbs in the rear sidemarkers..ive done that on my cabby, it passes.