Finding the policy is only the first step. For the policies you found, what did they say? If they say they’ll share your vehicle data with third parties whenever they want, that’s not any better, from a purchase decision-making perspective, than no policy at all.

Does the GDPR have an exclusion for legacy industries?

It's a little incredulous to have "hope" for Audi. This is the company that had self-driving cars in the 1980 that could drive from your garage into the swimming pool through the back wall. I did see a 10-cylinder Audi once but it my heart Audi is like Yugo or Trabant, not a premium car maker.