Thrifty, Munich no thank you!
You are asking for trouble renting Thrifty (It's actually an agent for several cars) and not taking the insurance.
I got fed up with High prices from Hertz/Avis and rented them, many months later I got a letter from them claiming damage of over €800, which I can honestly tell you I did not do, thankfully AMEX settled with Thrifty.
I think as soon as they see that you don't take insurance a large Munich spotlight is trained on you.
Search for my story under my username to see.
Save money and rent from Hertz/Avis/Sixt, however check the car out before the rental like you were buying it!
You have been warned :0)