You guys aren't going to believe me but here's what just happened to me; I didn't really have a problem with video interference, but the stories of people getting more satellite reception inspired me to try the foil trick (and looping the GPS cable back under the shielding). I bought foil tape, and taped all over and covered it in packaging tape for insulation.
Here's what happens now: when I start video, my number of GPS satellites would drop! In fact it was so bad I couldn't get a distance read when filming (see screenshot below), it'd just say N/A.
Again I didn't have this problem BEFORE the tinfoil, so...like the opposite of the success story everyone is reporting. For me adding foil actually CAUSED the problem you're all trying to solve.
Anyone know what's going on? I ripped out the tinfoil and it seems back to normal...thanks!