my van has a double front passenger seat. Is it possible to replace this with a single passenger seat ? when I asked my local dealer about this, they said you could not change this because there is an air bag in the double seat that the on board computer needs to recognise. the single seat does not have this. does any one know anything about this ?

sounds right,suppose you could do it but would cost alot.

I believe you can do it. The system is looking for a resistance to tell it that the seat belt pre-tensioner is there. You can, I'm told, get resistors to replace the pre-tensioner or you could leave the belt mechanism in when you remove the double seat and tuck it out of the way somewhere. I'm doing the same on a 2004 camper conversion.
Find a dealer that's better !!