The next upgrade was presented at the London Motor Show in October 1966. Besides receiving the larger 1275 cc engine (which disappointed enthusiasts by being in a lower state of tune than that of the Mini-Cooper 'S'), the Mark IV and its cousin the Mark III MG Midget had several changes which were more than cosmetic. Most notable is the change from a removable convertible top, which had to be stowed in the boot, to a permanently affixed, folding top of greatly improved design, which was much easier to use. Separate brake and clutch master cylinders were fitted, as car manufacturers' thoughts began to turn to making their products safer. On US market versions the larger engine sacrificed some of its performance from 1968 on, through the use of smog pumps and other modifications to comply with federal emission control requirements. 1969 was the final year the Sprite was exported to the US. At the same time reversing lamps were made a standard fitment and the cars' electrical system was switched to negative earth and powered by an alternator rather than a dynamo. This was also the first year that reclining seats were fitted.