A few months ago I purchased an aftermarket rear diffuser for my XK and had it painted to match the body color. Well, after looking at it for about a week I thought that black may be better suited for the diffuser but did not want to have it painted black in case it did not look good - so I decided to use black plasti dip and re-install it. 4 mos have passed and I do like the black look so i removed the dip and will now actually be painting it black. The dip was still like new, no tears or blemishes and came off really easy. The only reason I am actually going to paint it, is that the dip is a bit rough and when I wash the diffuser the microfiber cloths leave a bit of 'residue' behind. I posted this as a FYI in case you are planning any mods and are unsure of a colour…. plasti dip is a very cheap reversible option to try out colours.

 

So you know, there is also a Plasti-Dip Glosserizer, or some such thing. It's a gloss(ish) clear. I've used it as a temporary Clear Bra and it works fantastically. While it still has a bit of the texture, it is vastly smoother than straight colored Plasti-Dip.
Also, for a bit more coin, the Rust Oleum Clear Semi-Gloss Clear Peel Coat works wonderfully well also and may be a bit smoother.

 

Thanks Cee Jay - yes I was aware of the other products but still had half a can of Plasti dip so I used that. Just finished painting it black and just reinstalled it. Pic attached.