Some IROCs I've seen here have one thin stripe going around the entire car, usually in blue or gray, just above the ground effects. Anyone know what years this came on? More specifically, are they on any 91-92 Z28s or RSs?

Actually it is a double stripe. But on black cars, like mine, it looks like a single stripe, because the black part of the stripe doesn't show on a black car. Any other Iroc-z with a single color stripe is aftermarket.

definetly not from the factory like that