Quick search shows this could well be the right type though there is several choices, the tray size is the deciding factor?
http://www.batterymegastore.co.uk/varta-c30.html
Back to the very first post, is their a connection between the lack of seat belt alarm and the airbag issue? the seat connections have been checked(both)?
Is this problema solved? i have the same issue and i can't solve it!