Exterior Engine Lid Detailing Tips

Hello all,

Just purchased a new to me 1990 348 this week, and I had a couple questions about proper care for some of the pieces on the car. The attached photo shows the two areas I need to learn more about!
1. The engine lid cover has a black piece on it with a matte type finish. I have no idea if this is painted metal or a plastic panel. The appearance looks a little mottled, and went over it with some Griot's speed shine, and it returned quickly to a matte finish, but still slightly mottled looking. Is this supposed to be matte, or should I be putting something on it to UV protect and clean it up? What do you all recommend for care in this area?
2. The covers over the rear lights are also a matte paint finish right now. What is recommended for these bars?

Appreciate all the knowledge and tips!
Thanks.

 

Thanks for the suggestions, and I'll look into them.

Used some wax on the bars last night, and it was a deep rich black color, then went back to a slightly satin finish after I hand rubbed on some wax and it dried. I kind of liked the deeper black gloss color. I'll see if there's something out there.

 

Just to close the loop, used Meguiar's back to black, and it seemed to work on the rear bars really well. Brightened them up and restored the look quite well. It also helped with the look of the top of the engine cover, but left a slightly greasy finish. Never seen this product do this before, so it's a little new to me. Hopefully that fades soon. I did end up using a lot of product though to ensure even coverage.