Performance Gauges Designed to Suit Your MINI Marshall Instruments has developed a unique line of performance gauges specifically for the MINI Cooper Hardtop, Clubman, Convertible or Countryman. Available gauge options include a mechanical vacuum/boost gauge and Voltmeter. We also offer full sweep stepper motor driven Oil pressure, Water temperature, and Oil temperature. Each of these electronic gauges features one-touch peak recall and user programmable high/low full dial warning functions. Scroll down the page to see a demonstration video for these functions.