I don't think Germany is extremely outstanding in this point (the activity itself), but it seems (as you describe) that it's the german groups that are trying to "keep in contact" with right groups all over the world. IIRC the netherlands have an even bigger activity of right wing groups in their country, but they keep in inside Holland or travel to Germany only. It could also be, that American right wing groups (or right wing gruops in ANY country) might try to get in contact with German groups, as it have been germans who had the NAZI gouvernment.
EDIT: Maybe i'm not speaking clearly here, but I think German right wing groups enjoy some sort of "respect" by right wing groups from otehr countries.