Mine are yuck. What have you guys used with success to give it a long lasting matte finish? Read some have used the 303 Aerospace. Might be good as I can use it for the rest of the interior and maybe engine bay plastics/rubber? How long lasting is it?

Back to black?

Nothing short of a dye is going to provide a long lasting look. 303 is great but as soon as it rains it washes off pretty much. A silicone based product will last longer than a water based one, but many shy away from silicone based products. I personally use 303, but I just have to live with its lack of durability, in hopes that I can prevent the fading rather than trying to cover it up at a later time

I had used Back to Black on my '04's valences, it helped, but this will give it a bit of a sheen. Try it on a spot, like under the door, on the kick plate area. I don't know why that black was so easily marked, that was one of my peeves with the '04

I've found that klasse aio does a good job of not fading as soon as it gets wet. 6-7 weeks of a semi-gloss/egg shell.

I myself also use 303 AP and back to black. But with Back to black, I say you tape around the trim.

back to black FTW!

I just grabbed some back to black and put it on yesterday. I'll see how well it holds up. My side mirror mounts look terrible.

Okay I did my chaulky mirrors and a few days ago and it seems to be holding up well.
I did the lower valances as well and will monitor for lasting life. Kinda attracts dirt but I sorta put it on heavy for the 1st application. then I wiped it after a day. Just experimenting with how to use.

I have an 04 coupe that had the chalky (used to be dark) areas by the mirrors. I was told to use Scratch-X to get rid of the oxidation. I did this and it worked and looks great. You might want to consider it to remove the oxidation. I'd try a small hidden area first.

Nice idea. I do have plastic polish. But the B to B seems to be holding up well after 1 week.

I use turtlewax tire gel on the black plastic mirror trim. seems to last about a month or so.

Update. side mirrors are still looking great. 2 weeks and 2 car washes later.

Does it look even? I've use b2b before and could never get it to look even

Well I'll have to take a close look. I applied it once sorta thick and rubbed it off. then took a cloth with b2b on it and applied another coat.

I wasn't sitting there examining how even it is. I don't notice it being uneven.

It's 10x better then the chaulky sh1tty look it had before!

It does take a little extra work to get it looking good, I had a time of it, but it looked better in the end. That was one huge minus for the early sedan.