Planning to travel to Germany summer 2014. Fly in and out of Frankfurt. 7-8 days. Will rent a car and self-drive. We don't enjoy rail travel, as it's too confining.Two travelers, me and my husband. Want to first go to Lutherstadt Wittenberg and Erfurt, but not go into Berlin. Then back to Frankfurt and possibly do some day trips or overnight trips to the Black Forest area and a short Rhine River cruise. We will also avoid Munich. Many other things we would like to see but won't have time on this trip. Are we being too ambitious to try to squeeze all these things in?