I haven't had an issue. Here there is no cell phone signal but the GPS was still working even when I went through thick bush with trees above the defender.

 

Well if you're going to post a pic of your Defender in Africa with an elephant, I'm going to have to post mine when I saw that rhino....... in East Texas....

 

hahaha sorry it was the best picture showing my roof rack from the back.

Nice Rhino and defender btw. Do you know how to tell if its a black rhino or white rhino? By the shape of its mouth. Black rhino has a pointy mouth and white has a flat mouth. That looks like a black rhino. (im being serious) So that was a good spot as the black are much more scarce.