 The Saab 900 Aero was introduced for the 1984 model year, or as it was known in the U.S. "Special Performance Group" (SPG).The Aero/SPG incorporated (depending on the market and model year) a body skirt; a sport-suspension (1987+) that included shorter, stiffer springs, stiffer shocks, and sway bars; leather seats; premium stereo; and air conditioning.Each of these features could, of course, be ordered independently from Saab's Accessories Catalog for fitment to standard models.