I plan to weather my R2 and I noticed when I sanded the rear door
in the cracks around the panels it got a off white look and the
actual part that the sand paper did hit, It got a brighter white.
So what I'm thinking is to sand the entire body to match the rear door
then do the weathering.
After the weathering is done it should add a nice effect around the panels
and really look more authentic.
I don't plan to go extreme with the weathering, Just enough to give
it some character and the panels will be more noticeable in the sunlight.
R2 in the Empire Strikes Back is the model I'm using and the weathering
was mild in most of the movie.