Having done some research on audio upgrade on my w203, I've been convinced I don't have Bose upgrade, hence no fibre optics, and I've since bought a Pioneer HU with all the right harness and leads to replace audio 20. I took apart the dashboard this afternoon, only to find the dreaded orange cables, and a label on the audio 20 that says class 1 laser product. I don't have Bose upgrade (certainly no marks on the speaker grilles, and no amp anywhere to be found) but is it possible I still have fibre optics running in the car? If that's the case, what do I have to do to fit my new head unit? Is it a complete speaker wire rewire throughout the car? I really don't fancy having to do that if I can help it...