Two big problems that I encounter with BMW's almost daily, German rubber. The control arm bushings, boots, etc. last around three years, then start deteriorating, hoses last another year or two longer. Then you're gonna need replacing all the gaskets, sealants, every three to four years.
Lucas engineers, when the British Auto Industry tanked, moved across the channel and went to work for MB/BMW/Audi/Porsche.
i.e. the electrics, especially relays, wire harness connectors do NOT last....
Oh, along with the rubber deterioration, don't forget plastic deterioration, the relay and terminal connectors and holders crumble with age.