Don't forget that even if your jack doesn't fit under the car at first there's always a chance that you can pump some air into the tyre so that there's enough room. Obviously, that does depend on the nature of the punctures though.
@mik1ee. By collapse, do you mean actually collapsed (ie. failed) or 'just' toppled over? If the former, have you got a picture - if so, I'd be sending it to VW for a comment. Personally, I took one look at mine when I first got the van and vowed that it would only ever be used in an extreme emergency.