In the late '90s the German government mandated that every bit of a car be recyclable. BMW went with soy-based insulation on the wiring and biodegradable plastic in the cooling system. Hence, the first thing you do on any BMW is trash the cooling system and buy aluminum pieces. BMW could have done it at the factory, but the ultimate driving machines needed to be made cheaply. Look on FB Marketplace and I'll bet you can find at least three E36/E46 BMWs with cooked motors for sale, cheap. I think the wiring is more of a problem on the 5 and 7 series, where they ran enough computing power to monitor a manned Mars space flight.
Any which way, it was a rough decade for BMW, reliability-wise, and even knowing as much as I do about wrenching, I wouldn't own a BMW out of warranty. I think that now they've improved the plastics technology and have cars that can be both absolutely recyclable and more reliable.