I took delivery of my Sequence 20L the first week of August. I realized the bathroom medicine cabinet door was a problem by the time I arrived 45min. later, for our first night in our new Sequence. After several attempts over the next few weeks I came up with a very easy fix.
I attached 2 'super strong' rare earth magnets one on top of the other (reason for a second read on down) to the right hand side middle of the mirror glass door. I attached a metal clip, identical to the original one, at the bottom of the mirror, over the edge of the mirrored glass door. I found the sticky tape supplied with the magnets wasn't up to the task so I reattached with marine epoxy putty.
Now, after several more outings it hasn't come open once while driving.
WHY 2 Magnets? I found that by placing a second magnet on top of the glued magnet, it held the door off enough to make a nice strong connection. I left the original magnetic catch in place at the bottom of the mirrored door.
Parts:Amazon - the magnets
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
Parts: Amazon - the metal clip
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1