I have 2013 XJ. Realised my sticky buttons problem is result of using leather cleaner, or dash board cleaner. These buttons can only be cleaned with cloth and water, nothing else. Otherwise the creamy polish leaves a coat on the button which becomes sticky when mixed with dust and air... apart from replacement is to slowly “scrap” out the stickiness with damp lint cloth dapped with water. Have to use a clean portion of the cloth for every swipe. I tried using solvent (nail polish remover, window cleaner, etc...) the button marking will be erased off. Then you get rid of sticky but get a “botak” button with no marking. I spent 2 hours doing it in the cockpit with cloth and water until fingers cramped. At least it’s not sticky now and the button marking is still readable.