Well if you're talking about a seam on the actual, real world tank, for what I've been told, after a while in combat, most of the rubber part was gone anyways.

As for the scale model part, depend on the type of tank and manufacturer, you're going to have a different type of seams to deal with.

For example, Tamiya Shermans, the seam is a small one in the middle, but the Tamiya A1 Abrams there is a serious ridge at the edge of the wheels that needs to be removed.