Kind of similar I guess: I really like "lower tech", pragmatic solutions to mechanical problems that need solving. Moving a cars windshield wipers with the vacuum produced from pistons or propelling the wiper fluid with the pressurized air from the spare tire is so neat. I get that it isn't ideal and has its own drawbacks, but it has character dammit. I'm just so impressed by old school, mechanical solutions that take thrift and thinking outside the box when the answer in the modern day is usually just add more parts and make everything more complicated