What If Car Companies Worked Like Harley-Davidson?

Harley has been building functionally the same basic bike for, what is it, 300 years now? Little has forced them to change its styling or design over time. What if car companies could do the same thing?

I imagine Fiat-Chrysler would still be cranking out 1970s Plymouth Barracudas if it could.

What other cars do you think would still be around, much in the way Harley is today?