Generally good at the Hansa-Strasse. Very good: Take tram line 13 (Strassenbahnlinie) until Friedensstrasse, go right at the Hansastrasse (to the north), pass the McDonald's, underneath the railway bridge, 500 meter past Kleingärten (?). There you will see a Shell service station. The Hansastrasse is an access to the A4, in both directions, and to Berlin.
There are also often hitchhikers right behind the railway station Neustadt.