Excellent write up and pictures. You took a similar trip to what I am trying to plan. I leave June 13th to pick up E90 335i. Now after reading your trip and seeing your pictures, I'm getting very excited.
One stop on my list is the Hintertuxer glacier to try to do some snowboarding. Through the help of others on this board, I've discovered they are open 365 days/year.
Were you in this area of Tirol and can you make any recommendations on places to stay? You mentioned many hikes, but curious if you attempted skiing.
I'm wrestling with just driving to that particular area and trying to find a local place to stay one night, or spend 2 nights in Innsbruck and use it as a staging area.
Enjoy the car