So, here is a new one for me. I've got a new DJI Phantom 3 drone. For the past 3-4 weeks it has been working well, but occasionally throwing compass errors on start-up. After a long drive today, I couldn't get the compass corrected at all to start up the drone (in the middle of a field). After some research online, I discovered that if the compass becomes exposed to a huge magnetic field it needs to be degaussed and the IMU and compass on the drone needs recalibrating. It took a LOT of degaussing to get it back to normal, but it got me thinking... what caused it? When I travel with the drone it is in a nylon case in my trunk, right above the rear coil on my P85D. Hmmm. That might be causing a magnetic field. So, I did a bunch of tests. Using a standard field compass in liquid, when I put it in the car in the back it pegs the needle to the floor (suspended in liquid) and the compass needle won't move -- with the car off. I have also found significant compass interference, just by putting it in the passenger seat, passenger floor (front coil?) and moderate amounts around the car. In a drive test, the rear compass test stays pegged while driving, turning, u-turning, etc. Not surprising, given what lies a foot away, but makes me realize that anything that is magnetic sensitive (e.g. a precision drone) might need to be shielded. I couldn't find a reliable place in the car (besides the drivers seat) without any compass interference. To test my theory, I took the degaussed drone five miles away in another car (one of those ICE cars) and no issue on start-up. Then I took it to the same field in the back of my Tesla and it needed compass calibration three times to get it started. I know there are other threads discussing EMF, but does anyone have a good solution to shield sensitive equipment in the back of a P85D? I can't be seen flying my drone and driving a gas vehicle.