ok who cleans their rear wheel arches, it has a silly fabric liner (why couldn't it have had plastic like fronts), I usually clean it when dry with a dry cloth as the bits fall off, but I skin my fingers and hands . Tried blasting with hose pipe but does't remove anything much.

DO suggested APC then hose it, would this break the muck down enough to blast it off ?

Don't really like to blast water under the arches, you can't be sure where and what nooks & crannies it goes in.

I don't like dirty arches.

Straight from my Autoglym cleaning manual: (it was free )

"1. Spray (Autoglym) engine and machine cleaner under the arches and on all muddy areas. This is a strong detergent and should be left for several minutes to let it penetrate and loosen the dirt"

"2. Use a stiff brush or spatula to remove any caked-on mud under the arches. Do not try to use something sharp such as a screwdriver as it could scratch and damage the inner wing."

"3. Hose off the mud with a thin jet and use your gloved hand to release stubborn mud from the inner wheel arch. Take great care as there may be sharp projections under the wing"

There you go mate, hope that helped

yep thanks.