The trim is clear anodized. When it's new, it's great for keeping the shine, but as it ages, it becomes difficult to keep looking good.
You'll have to go the route suggested in Turbo IIs post to really make it shine. You're basically going through the anodized surface and getting further down to the aluminum. The down side of this is that it will be exposed to the atmosphere and will oxidize as a result of exposure to our environment. It will most likely require repolishing from time-to-time to keep it fresh-looking.
I would imagine a plating shop could reanodize it for you after polishing, but I have no idea as to cost. This should essentially put it back to "new" condition/durability.
As to blacking out: I have blacked it out on several cars. Just make sure to sand well with at least 400 grit, then etch prime, and use the semiflat black of choice. In my case, I used semi-flat Krylon for coverage, and a cheap off-brand semi-flat black to get the sheen just right.
I have some trim pieces on my chebby done in satin black powdercoat, works great. Unfortunately, my buddy that has the powdercoat rig has not yet built a dedicated oven, so all we're doing so far is pieces that will fit in a conventional oven.
