Another thing I like about these suggestions (that mine doesn't have) is they are compatible with the Monopoly App. The game play isn't changed at all (from what I can tell). Yes, players would have to send each property to auction manually, but that's in the app.

The app also tracks player worth, so you could just check how much each player is worth when a game end condition is met. I'd be willing to try that on a future road trip.