Mike W. wrote: Oct 24, 2023 5:01 PM
I've used a number of products over the years with little success. Some are better than others, or perhaps I should say some are worse than others, but they're all oily. I was especially disappointed in Meguiars product as I've had pretty good luck with most of their products, but not this one. Chemical Guys might be almost up into the mediocre category, but no better. Really Amour All is as good as most of them IMO. As I said, none of them I've tried last particularly long, I typically apply it after a wax job, just kind of icing on cake.
Depending on how nice you really want it, buying new is an option, it appears they're still available.
https://www.getbmwparts.com/oem-parts/b ... 1131927405
https://www.schmiedmann.com/en/cata-ol?q=51131927405#
This is true for the standard trim pieces although you should check with online suppliers to be sure. If you're talking about Shadowline, 2 or 3 of the components are NLA, which is the problem I encountered when I tackled this project earlier this year. For the money and the effort, if they're available and not prohibitively expensive, this is the best option for the time and effort. Swapping the pieces out is easy and the time it will take to refinish the trim pieces, treat them, keep them treated and looking new will pale in comparison to the cost for new pieces.
The problem is that most of the existing pieces are dinged, dented, scratched and/or deteriorated so you have to put in the effort to refinish them first then go about treating them. I did all this, took photos and was going to add it to my M535i restoration page but not gotten around to it yet.
First step was to thoroughly strip off all previous treatment (strong degreasers, soap, even acetone). Careful not to strip off the small silver band on the standard pieces.
Next I used both acetone and 6000 wet sandpaper to even out the surfaces.
Then start applying the treatment of your choice. For me I tested a few and landed on this stuff: Car Guys Plastic Restorer
https://www.amazon.com/dp/B071FRWWRF/?c ... _lig_dp_it
It goes on well and not too greasy, but it a topical treatment so it does have a finite application life. For mine, it was important to make the refinished parts match the new ones, so there was a bit of experimentation and redo involved; but if you aren't doing that then I would apply, buff in/off, re-apply, so on, so on a few times to work it into the rubber pieces. The goal is to make it look refreshed without it being too greasy.
The other product I usually have used on all exterior rubber parts was something not made anymore (memory fails me at the moment and the only place it is is not near here) but it is a great rubber & tire treatment. With this you will want to buff it into the rubber in successive layers.
I have been trying to apply this method to restoring the crazed rubber surfaces on the MTech rear spoiler lip with limited success (only because the damage is too great.
