Definitely want pics mate
I had a look at the MPS6 of one of the guys who works in my office and it looked and felt like a powder-coated metal? Didn't seem painted. It's definitely not clear coated in any way, so any sort of polish would be out
You can try a plastic trim restorer like Carpro Perle or PreWow/Black Wow (which is what I use). That may help. Otherwise it might be a case of lightly sanding them and respraying them
This is the product I use: Black WOW + Pre-WOW Trim Restorer Kit
Not sure if you can get it in kit for like this in Scotland, but there are two main products in the kit. Pre Wow, which is a trim cleaner only (an quite often all that's needed), and Black Wow, which is a restorer (for heavily faded trim that Pre Wow doesn't bring back)
I know that the Black Wow lasts longer than Carpro Perle (up to several months longer). So it might be the better option to try if you can get hold of it