It's a Zen thing
I often get the same sound when I drive my Crossfire. First, I get the rush of 1st, 2nd and third gear, full throttle down the entrance ramp. Then I get the perma grin.
And then I get the HMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM MMMMMMMMMMMMM.
Very Zen.
roadster with a stick