I did that first to see how I liked it. Then later pulled it off, light scuffing with some sand paper, primer, couple coats of black, couple coats of clear, and polished. The polishing was the hardest. I had to turn the buffer over clamp it on and then move the cap around over it.
Do you have a before and after? It kind of reminds me of the rearview mirror cover I bought. I was not happy about what I got for the price, I should have just PlastiDip'd the dang thing.
All the covers are thin and flexible until you stick them on then they do not move. I put one on mine at the Dragon to see if I like the look of it blacked out and I did. The problem with the plastic covers is if you don't take care of them (seal the color) they fade and then you have to rip them off. I just skipped a step and went with Plasti dip and a layer of Penetrol.