Did you use some solvent on the plastic wheel that may have eaten it; softened it up? Strange that it would just get sticky for no reason other than spilling something on it. Might want to look at the container of the cleaner you used on it and see if it was plastic friendly.
As for the plate locale cover, those are a rare gem around here. Maybe more rare than the roof rails. MD has a front tag law so I have to keep my tag on, and I have the cover, but I am gonna hold onto it until someone offers me $1,000,000.01 for it.
Gary Noonan
'01 S/C VX / '18 Forester XT