Wow, I'm amazed how quickly the follow up came through this time. Thanks, Tony, for getting back to me right away. As I understand it, there are 2 units: the MDC, and the Unit 51 (I may have that wrong because I didn't write them…"
I've inquired at the dealership regarding adding Cruise Control to my SmartCar and they are hesitant to offer much advise other than saying it's being considered in the future, and that it can be added by some independent mechanics. I'd be interersted in knowing if anyone has done that. I won't even try any long distance driving without it.