The drive from Oberstdorf to Ulm takes you further north east past Munich. Taking highway 19 north, connecting to 7 north will bring you through two other cities, Kempten and Memmingen. Kempten has many fun things to do, but one of their greatest features is their Achaologischer Park Cambodunum.
Getting off at north 300, Memmingen is the next town on the way to Ulm. As is in most cities in Germany, stopping by a local brewery is a great way to experience a big part of the town; the beer. Memmingen has about 3 main breweries, but one that stands out is Meckatzer Löwenbräu Benedikt Weiß KG. One of the best local brews is the Memminger.
Continue up highway 28 and you will find yourself in the beautiful German town of Ulm.