baking normalmaps without getting seams from other meshes in the model....

hey guys and gals, mayube you can help. I am looking to bake my model without having to break up my model into multiple seperate pieces. the issue I am getting is seams/lines from the near by model/meshes baking into the maps of the neighboring mesh. I am baking normalmaps for a human sized drone, and I get the issue where the nearby meshes "bake" into the mesh I am baking currently or all them at once. How do I avoid this issue? is there a setting ? I tried a cage file but it didn't work, still baked the neighboring meshes into my normalmaps e.g. the hull and the canopy glass baking into it. thoughts on this? I'd greatly appreciate it thank you.