Installing the new Dometic FJX4 2200 aircon on a Grand California is a tight fit! If you order a new Grand California with aircon factory fitted, they put it in place of the rear skylight, if you don’t, the hole cut for the skylight is too big to install an aircon. We have overcome this problem on the Grand California 600 and the Grand California 680. There is just enough room on both vehicles to install the unit next to the bathroom door. We do need to cut a new hole, but the area is very well supported with floor to ceiling walls, so it will not cause any structural problems