Greatest surprise of the day comes from BMW M’s Facebook post about a one-off V12 BMW Z3 Prototype. No further information were released on the Facebook page, but we believe the V12 engine is the 5.4 liter M73 which produces 326 hp @ 5000 rpm, and 490 N-m (361 lb·ft) @ 3900 rpm. The engine will be put into a compact package so weight distribution will be a problem. Clearly, it will never reach actual production.