During his loser period, the character is tricked by the "Winsome Welshmen", Dunstan and Dudley Dorchester, into buying the Swiftmobile, a bit of a wreck, in an attempt to impress the lady he likes. The vehicle is sold as a 1924 4-litre Swiftmobile, with the old type high point bevel transmission (for which 1922 was a good year). Spare parts were not needed, since the company went out of business because they were too good. Palfrey parts with 695 guineas. The car is a complete disaster, backfiring and unwieldy. Needless to say, it fails to impress Palfrey's lady friend.
After attending the "School of Lifemanship", Palfrey returns the Swiftmobile to the Winsome Welshmen and claims he had the car up to 115mph, chasing a new Jaguar along the North Circular Road to Ealing, and that the Swiftmobile is, in fact, a 1925, a supercharged model, of which, only 6 were ever made. The valve seats are different, and the vehicle runs on a Petrol:Meths 1:2 mixture. Incredibly, they buy his story and agree to swap for an ex-works Austin Healey and to pay Palfrey £100 in addition!
Ok, so why is this story in a Royal Enfield related blog? Part of the argument in which Palfrey convinces the Winsome Welshmen to take the car back at a loss on their part takes place in front of a Royal Enfield Meteor sidecar rig, The Swiftmobile was sold by the studio for £30 after the film. It was bought in 2003 for £110,000.