We are planning to take our son to a school term in Ulm, Germany the first week of October. We have been to Frankfort before and drove to some of the southern Germany destinations - Baden, Black Forest, Rothenburg. Looking at the map, it would seem that travel to Switzerland, Austria would be best. Not sure if it is better to rent a car, or are there any guided tours available, and what should we make sure we see. Would appreciate any insight. Thanks.