I was like last month old when a cover performance finally suggested it could be "deuce", like the coupe, instead. I knew "douche" was wrong, but I never had the presence to ask.
Deuce is correct. The tune that everyone knows is actually a cover by Manfred Mann of Springsteen’s original (yes, Bruce Springsteen). The lyrics were tweaked a bit. Springsteen’s lyrics are “Blinded by the light, cut loose like a deuce, another runner in the night”.