303 Aerospace protectant is the product to use on plastic, rubber, vinyl, etc. It's a great tire UV blocker/protectant and the only one that works. NOT a "dressing" like ArmourAll junk and all the others that contain petroleum distillates. Sure it makes them shiney but NOT what you want to use.
http://www.303produc...-protectant.cfm
http://www.303produc...ation_guide.htm
I use it on our RV tires and decals and all plastic and rubber parts/trim on the vehicles.
Most marine and RV stores carry 303 and Walmart has it online and maybe instore.