A quick detailer (I prefer Mothers) will clean the surface. But if you have a good looking surface, just simply wash with water and a little car wash soap. To protect the finish, I use Mothers Protectant or Protect, forget which but there is only one. If the finish needs restoring, use Back to Black. This is a wonderful product that will restore that factory look as well as remove any white wax residue.
Basically, you want a product that will protect the plastic, but not change the nature of the finish. Mothers Prot. does this as well as Meguiars has a product that does this. But starting with the Quick Detail or washing would always be the first step.
I wipe all the surfaces including the windshield with Lucas Slick Mist and a micro fiber cloth after most rides. On the Spyder it only takes a few minutes and doing that at least after no more than two rides has kept mine looking better than showroom condition. If it has dirt or road grit on it or you rode in the rain, then wash it first.