We will arrive in Munich on Christmas day for 3 days, Saturday, Sunday, and Monday (when most of the museums will be closed). Will anything be open? Also, should we pick up a car at the airport, or on the way out of Munich?
Car will be a giant burden in Munich. Public transport is just too cheap and easy.
You're better off posting this question in the GERMANY section - you have it posted in REVIEWS, which is meant for you to write a REVIEW of your trip. Go under GERMANY and repost. Also, you don't need a car in Munich. Or at all for that matter - the train is too easy