I'm looking to change the rubber seals in my car as some of them are very brittle already. Do you guys have an idea where I can buy them?

Edit, I found this in eBay. Is this any good? -- https://www.ebay.com/itm/131919628930

Generally anything but Genuine MB is to be avoided (doesn't fit right), but in the last couple of years some satisfactory aftermarket seals have come out of Turkey. I can only speak for two parts that are no longer available as MB genuine for my c126--the lower cowl weatherstripping, and outer door window "scrapers"--and those needed sharp cleanup cuts on the edges. I can't speak for the windshields/doors etc, and if it's from the same manufacturer or not. You could always try--if you have a garage to keep it from weather should the seals not fit properly. The price would be waaaay to good to be true were the genuine MB (total over $2,000) for all those.