My center armrest (EX) is getting quite patches of whiteness (looks faded) due to the material of the fabric and the fact that my right elbow is resting on it and rubbing on it when I drive.

I tried to clean it with some water but doesn't seem to do the trick.
Anyone else have this issue? Has anyone covered or placed something on their armrest to prevent this??

 

Congratulations, you're the only person whose elbow can actually reach the armrest. You must have a 7' wingspan!

Seriously though, you could try one of these to cover and protect it:

 

Those white patches are a combination of soap and dead skin.....the armrest material acts like sandpaper, and rubs your skin off. A cover should solve your problem. As an alternative, you might try an exfoliating product, like this: