Yep, pyramid plastics do them.
http://pyramid-plastics.co.uk/extenda_fendax.html I brought mine from P&H who ordered it in for me.
A couple of words of warning though.
Make sure it is correctly fitted. Mine was fitted poorly by said dealer, and in the 25 mile ride home it was constantly rubbing the front tyre !
Also, the centre screw must have its point removed else it can wear a groove in the tyre.
If you buy one I'd strongly advise taking the front guard off in order to fit it correctly (the dealer didn't do this on mine - got a new guard out of them though so not all bad).
Cheers,
John.