Car reviewers traditionally harp of the Porsche 911 Turbo for being a little quiet, the twin turbos muffling the exhaust note. This particular 993 hillclimb car doesn't have that problem.
I can't quite put my finger on what this car sounds like. Maybe swarms of Goliath Beetles being fed into a turboprop? I'm not sure. Any further analogies are welcome.
And if you have indeed heard a Porsche Turbo that sounds like this, let me know.
(Hat tip to Jacques L'Autre!)