Hi Gillian - we're just trialling an air mattress, actually beneath the existing VW mattress (2010 version - not a "comfort" mattress). We're planning on leaving it in situ when lowering the roof, after releasing the valve on the air mattress (I know they're self inflating but I don't think that will be a problem as long as we lower the roof quickly). We haven't tried it yet - we'll be careful!
I've found it to be a great improvement - not having to turn over every 10 minutes to relieve discomfort where my hips hit the mattress
Just wondered how you were doing with it?
Ian