CAR OF THE WEEK: JAGUAR'S XKR
There's mechanical grind in the background. It's felt more than heard, and as the speed increases it gets more obvious. It's the supercharger winding up as the big engine's revs rise and the car blasts down the road.
Ref. https://www.stuff.co.nz/hlc/1,,93498~4125635a30~,00.html