John's VX is the prettiest VX I've personally laid eyes on and he knows what he's doing. The insert is a white material covered in matte paint, so you can safely wax it. You and I both may want to consider doing that. I use Meguiar's tire gel on mine routinely for a touch-up and it causes no ill effects. It will attract dust and it will not adhere as well as it does on the cladding, though.

Tone makes a good point, but I have never gotten mine shiny enough to cause that problem. I'd say clean it up good (preferably with a clay bar) and then wax it. If the wax were to become an issue, wash just the insert with a good dishwashing detergent and it'll strip the wax off, no harm done.