Got these'Aspheric' wide angle mirrors off eBay from - Click Here -
Description: CITROEN C4 REPLACEMENT RIGHT WING MIRROR GLASS 035RAS
Description: CITROEN C4 REPLACEMENT LEFT WING MIRROR GLASS 035LAS
Price: £7.99 Each
These do work brilliantly however they don't have the large plastic frame holder like the OEM ones do and are no good if you have heated mirrors
They didn't look great because of the missing 'frame' so I simply stuck the mirror on top of the existing ones (they come ready with a large area of double sided tape btw)
Once on you can't really tell they are over the originals