Sometimes those little things to do just don’t get done. It took me ages to replace the old trims who broke off when I tried to remove them. Now I finally found a German company selling on Ebay (thanks to GMC people on facebook) who could deliver the right size 10cm and the exact same finish as the original. (http://stores.ebay.de/Febaus-Rolloshop/Kunststoffleisten). I paid 18 euro for 6 meter.
After cutting the length to size, the shape needs to be adjusted with a heat gun. Today I have done this. It is a bit off work as you have to heat (20 sec) and fold it and hold it until it cools (20sec) off every 10-15cm but after painting, I am satisfied with the result. The following pictures are from the internet. The curve is more like the original and not as the picture but you get an idea how to do it.
The final step is to paint it in the same color of the headliner and cabinets so it will blend in nicely and cut out some pieces now and then. To secure it on the metal I am thinking on using velcro tape glued on wood.
This is the result: