I'll stick this here because it's sort of related.

BA sold me a package (flight + car hire) which will arrive into Munich airport at 22:55. Unfortunately the Avis office will close at 23:00.

I shan't have any luggage and I've been there plenty of times before (and hopefully the flight will be on time) but are there any tips for this situation?

What I'd like to hear is that the desk will stay open for a few minutes if there are confirmed bookings due in (and they have the flight number).