Moditech Rescue Solutions just posted some info on door mounted curtain airbags on Facebook. Here is a little more info. Take a look at the pictures below. The first one is a pic of behind the door trim of a Mercedes-Benz SLK. The second picture is a screenshot from Crash Recovery System of the same vehicle.
As you can see from the pictures the side curtain airbag is mounted in the door. It is designed to deploy up towards the roof. Also, notice the high pressure cylinder in the door near the A – Pillar. Because the occupant will be right next to the door, it may not be possible to pull the interior prior to cutting or crushing the door. The good news is you can anticipate this type of airbag on soft top and hard top convertibles or (if your department is fortunate enough to have a copy) utilize Crash Recovery System to locate the hazard. Check out some more info at http://www.moditech.com/rescue/index3.php?action=newsletter&detail=55 . Be careful crushing the door to get a purchase point or using the spreaders to remove the hinge side of the door!