Howard Heerey's Midland Garage then took over, renaming the car simply GTM. Heerey kept developing the car, reaching a third variant by 1971 (referred to as 1–3, for "model 1, variation 3"), when about 170 kits had been manufactured. This third model used the Mini's front bumper (earlier models had none) and the taillights of the Triumph Dolomite.
Howard Heerey's Midland Garage subsequently acquired the car, rebranding it as GTM. Heerey continued to refine the vehicle, producing a third version by 1971 (designated as 1–3), with approximately 170 kits manufactured prior to that point. This third model incorporated the Mini's front bumper and the taillights of the Triumph Dolomite.