Since the post has been revived, I thought I'd add to the fixes. I used Meguiars rubbing compound with great success and no damage to the white ">> and <<" markings.I have a 2009 550 clk cab. Not the entire dash, but the round section in the center with air vent controls, between the air vents, is sticky to the touch. Tried to clean with cleaner wipes and now there are surface scratches and it is still sticky.
The material seems different than any other part of the interior.