I just picked up a mega, and have a shepherd. Still experimenting…. But our best approach so far is fold the larger portion of the split bench down (the 60 side), which means the climb is only from street to floorboard on the 40 side. Then another step up from floorboard to flat floor on back of 60 side.
now the dog has large area on back of 60 side, and you still have the 40 side seat for a third person…. Though no center armrest.
if no third person, I suppose you could now fold down the 40 side, giving dog whole area. And retract the 40 seat & reverse for egress.
YES to trap door, sad when he missteps and activates it. Wondering if a thick dog bed would help avoid.
we‘ve always had him in back of SUV and are worried about him getting hurt (and hurting us as a projectile) in an accident. Hadn’t thought of a harness attached to childseat restraints. Will investigate!