So I took my Stillen roof spoiler to this fairly reputable body shop in Houston (they fix Porsches and other high end cars). I gave him the piece to paint with the paint color (K51 - Platinum Graphite) and had to insist on getting some sort of receipt just in case - he didn't want to bother with paperwork and estimates for a simple little job.

He also professionally did my grille Satin black. I'm happy with how the grille turned out, but the roof spoiler is a little dark.

When I put it up against the car where its supposed to go it looks too dark - but if I angle it just the right way the light hits it and it looks better - but in general just holding it up to the car it doesn't look right.

It has the little bit of flake and stuff in it, just dark. Is this just an issue from painting ABS plastic compared to the metal of the car and unavoidable? Or is this something I could go back and ask to have redone?

I'll try and get some photos tomorrow. It's close, but it's something I feel like I'm going to notice is wrong every time I walk to my car....

 

Matching a piece that butts up against the OE finish is extremely difficult to match.
One of the biggest problems is not just the color, but also how the flake gets laid down.
You can have two painters do the same panel with the same paint & have it turn out differently.
Paint lay down technique has a big effect on how the flake is suspended (direction) within the paint.

For them to match as closely as possible, they have to get close to how the factory paint is laid down.

I had the same matching problem when I had the side sills painted on my '04 G.
They repainted them a second time & got them MUCH closer. (but it still wasn't perfect)
The second time they took my gas fill cover to tweak the color &
used it in the booth to try to match the lay down.