There was an electrified 4*120 at my field earlier this year that used magnets on the hatch... it blew off once that I know of, I beleive he just added stronger magnets.
Not sure how the hatch was actually done, if I remember right, it was built up as figment was considering.

Mountaineer, glad to see you back! Best wishes for baby#2 and mom! (and congrats!)