The driver's seat-base bolster on my Exclusive Tourer has 'collapsed', the foam's all crumbly under the leather and offers no support at all. The seat design is pretty poor really - every time you get in or out of the car, the right-hand bolster gets sat on, so it was always bound to give up eventually. Anyway, I've contacted loads of trim specialists, and not one has said anything but 'nah, can't help mate, the cover's bonded to the foam, you need a new one'.
So, I've just phoned the local Citroen dealer. £800....plus VAT for a seat base cover!! Holy ****!
Pete