Best sounding Bmw engine S65, sure? Anybody remember who producted V12 engine in Mclaren F1? Yes Bmw Motorsport. Then M1 Procar over 9000rpm revving M88- based Inline-six and ~1970 Launched E9 CSL "Batmobile" 3.5L I6 and 430bhp/8500rpm, then of course car what starts this E30 M3 S14. Funny that fourty years has past and now comes 3.0L I6t "only" 415bhp.
But this is best, 3.5L I6 and that sound when air going to engine.