I just found this
graph of Saab sales over the years. They grew steadily during the 80s and peaked in 87, which is around the time I remember I started seeing them everywhere. Then they took a nosedive.
Partway though the nosedive, GM acquired a majority stake in them (1990,) and slowly started to grow the brand again in the early-mid 90s. Then about 3-4 years ago, they took a nosedive again.