The mk4 Beetles have a dashboard made of a ridiculous rubber/plastic material that gets sticky when the sun heats it up.  Why VW chose to use this material is beyond me, but I know that the mini california duster is the ONLY product I've found that can successfully clean the dust off of the dashboard.  It sounds trivial, but this is a really great product for the reason that it achieves what no other product can (or so I've found).