I have third row seating and Cali Raised LED molle panels, so chances are, it wouldn't work for me at all.
If it did though, I would prefer the drivers side and to keep the passengers side electric easily accessible.
As for magnets vs. latches to keep it closed, magnets can be a PITA if you have anything that might stick to a magnet in the rear of the vehicle. My 4Runner is my fishing vehicle, so baits, hooks, pliers, my removable nav lights....it's all back there at some point and all of those could potentially find their way to the magnet. My preference would be to use dzus fasteners. Easy to remove and it would hold the panel securely in place.