Cheers, all!

I talked to a mechanic friend yesterday who works on MB and has the STAR system, $50 and he'll hunt through the programming to try to find where he can toggle temp, miles/km, and time (currently in 24hr, not 12).

Only downside is anytime the battery terminal comes unplugged, it is likely to revert back. At least I'll know and when the time comes to sell the car, I can get it switched back to miles.