The Original Swiftmobile.
School for Scoundrels (1959) is one of my all time favourite films for a number of reasons. Based on Stephen Potter's very dry Lifemanship and Gamesmanship series of books, detailing how to win without actually cheating, it is a classic British film, and although not an Ealing Comedy, it could, at first view, be taken as such.
The film has a great cast of leading role and bit part actors and actresses, and vehicles – Peter Jones as Dudley, Dennis Price as Dunstan, Janette Scott (daughter of Thora Hird) as April, and stars the great Alistair Sim as Stephen Potter, Terry Thomas as the arch-cad Raymond Delauney, Ian Carmichael as the hapless, love-struck Henry Palfrey, and, of course, the Swiftmobile.
In the film, Palfrey is deceived by the Winsome Welshmen, Dunstan and Dudley Dorchester, into buying the Swiftmobile, a bit of a wreck, in an attempt to impress April, for whose attentions he has locked horns with Delauney. 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). Spares parts are not needed, since the company went out of business because they were too good, although we are told that the company survived the depression. Palfrey parts with 695 guineas.
Later, as part of his oneupmanship, 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. He subsequently swaps the vehicle with Dudley and Dunstan for an ex-works Austin Healey 100/6 + £100.
The Swiftmobile was based upon a 1928 4.5 litre Open four-seater Bentley. It was first registered in December of that year with the mark XV634, which, I understand, it retains. There is very little known of its first 20 years or so. What can be confirmed is that a Bentley enthusiast used the vehicle, daily, as a commuter to Newbury, and that the vehicle then bore the mark DDB704, having an altogether different bodywork. The vehicle was subsequently raced, having a two-seater open body fitted, before being sold on.
The Associated British Picture Corporation bought the car, along with the disguised Aston Martin DB3S driven by Terry Thomas to use in the film. After filming had finished, the Swiftmobile was sold by the studio minus its two-seater bodywork for £50, in 1961. It then remained in the same ownership for 40 years, during whose tenure a replica Vanden Plas four-seater open coachwork was fitted, that it now sports, but the bonnet, chassis and engine all remain original.
The vehicle sold at auction in 2003 for £110,000.

The Austin Healey 100/6 featured in the film is equally as famed in its own right. It was a works press vehicle, having the additional tweaks to woo reporters, featuring in Road Test reports, and drove the circuits of Britain, in racing mode. The vehicle was rescued in the mid 1970’s, whence a long restoration project was started, and completed. Its whereabouts is unknown to me, having failed to reach the asking price in the region of £30,000, at auction.