It would be the basecoat (color) that faded. Clear rarely fades, it just cracks and flakes mostly. If it were anything to do with the clear, a goof wetsand and buff usually takes care of that.

What you can do is have the entire VX wetsanded down to the basecoat and then have a clear zapped over it. Its really not the funnest job for a paint shop, but painting after a wetsand (not grit sand) is clearly the best way to go if you want a great finish.

Yes, it costs a few bucks.