Lots of 1980s cars have standalone dinger units. Just like with mercedes the buzzer / dinger was part of the seatbelt reminder and lights on / key in ignition reminder unit. The only problem is lots of those dingers sound... not very good.

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1991 350SDL. 230,000 miles (new motor @ 150,000). Blown head gasket

Tesla Model 3. 205,000 miles. Been to 48 states!
Past: A fleet of VW TDIs.... including a V10,a Dieselgate Passat, and 2 ECOdiesels.
2014 Cadillac ELR
2013 Fiat 500E.