There were many companies that carried out conversions to the J2. Some of the more popular were Woodham Brothers, Central Garage (Paralanian), Cotswold, Bluebird, Martin Walters, Autosleeper, Calthorpe and Pitt and Car-Camper. Many of the ambulances had diesel engines which was their downfall as most were auctioned and broken down for their engines which were ideal for boats.