I have had the M3 digital speedo("V = mph or kph") "coded" into my BC. When I turn off the car, what ever screen I was last in... will be shown when I restart the car the next time.
You should find someone who does car coding in your area. Btw... you can also have the digital speedo coded to read actual vehicle speed or the "buffered value" that the speedometer reads(+3% to 5%). I have mine coded to read actual speed and it shows exactly what my GPS reads for vehicle speed!