I titled this thread "Radio won't ft all the way into the slot" so as to make it "searchable" for future, err, "searchers"

As some of us will know, many modern "head units" (car radios they used to be called

I used a length of D shaped rubber trim, glued to the radio case, to cover the sticky out bit, but it still looks a bit naff.
Does anyone have any simple tricks to :-
A) Make it fit all the way in.
or
B) Make it look neat even though it is sticking out 1/2 an inch.