jelag. I have been using 303 Aerospace Protectant for a long time, first as a UV protectant for the dashboard but use it for all other soft plastic
and rubber. It prevents the cracking of sun exposed tire sidewalls and dash tops. I even apply it to windshield wiper blades too. It is basically
a UV protectant and does not leave any shine for cosmetic purposes, just leaves the natural appearance. It is also used on pool covers and marine and is non toxic. It does
need to be re applied often as it doesn't last. Unlike the silicone oil based stuff, it doesn't leave a slick shine that can intensify the effects of the sun.
Tom