This is why a museum would be perfect. You’d have trained employees to maintain the cars, including taking them for a drive. Plus, you could even sell rides in some of them the way they sell rides in F1 cars. Add in car shows and a cycling of the cars on display the way museums don’t have their entire collection on display at all times, and the cars would probably hold up better in the long run.
Ideally, you’d do this with government money pulled from a wealth tax or a foundation rather than trusting some billionaire to do it and maintain the museum.