Hey Bob!
OK,I do have a solution.
I stripped out the trunk and drilled (with a hole saw) some 2 inch holes.This size,to allow me to shine a light in.
I could then pass through the wand of gunge!
Now then...this was pumping out POR 15 (they do NOT also make one called PEN 15!! )
Once I was sure I had covered around the entire wheelarch,I switched to the other side.
When I had done this,I did the offside again then the nearside,yknow,just to be sure.Also,it brings out the male ego in you with a squirty gun in your hand.Ohhh yeah.
We can see the difference so far this winter.No rot whatso