May 30, 2019 - 8:46 AM
Thank you for joining MySwissAlps! I do not recommend to hire a car in Switzerland and drop it in Germany. Not sure if that's your plan but this could be very expensive. Even if this does not apply, I consider traveling by train in Switzerland to be part of the experience. Often better than by car. For Germany it can be different if going to rural places. If you do drive, then the Brünig Pass is fine in August. It's not very high. It is curvy, but that should be doable if the driver pays attention to the road rather than the scenery. More information is here:
There are many must sees in Switzerland. With only two days available, you could also choose the Lucerne area as it's closer to Zurich. Very easy to reach by train. You could then hire a car on the day you depart for Germany.
By car from the Interlaken area to Oberstaufen would be taking the same route back until Zug, then take the A3 east and A13 north via Austria. You need a vignette for Austria, and one for Switzerland too but rental cars have those included.
Just some ideas to get started. Let us know if you have more questions.