When I think of an Icon of an era I think it's important to look at criteria such as
1) in hindsight did car really matter,
2) is it a decent performer that's fun to drive,
3) Is it rare enough that you usually have the only one at the show,
A car that you forgot that I believe meets all these criteria is the Audi Ur quattro. Only 664 were sold in the US - so it easily meets the rare criteria. With it's turocharged 5 cylinder engine and all wheel drive it can safely keep up with most cars on your lists on a twisty road.
Lastly, it is a car that was a game changer. After the Ur quattro the only cars to win World Rally Championships have been all wheel drive (AWD). And you do remember that Quattro was "outlawed" from IMSA racing because it gave Audi an "unfair advantage"
Is it a car that mattered? The impact of AWD and turbocharging on the luxury/sports car segment 30 years later has been substantial with 30 percent of cars sold in this segment having AWD. It's impact on rally and hill climb cars even larger.
