'00 E320 outside temperature glitch?

[The Godfather]

Over Xmas, I drove to Vegas. I Drove on a road that was a good 30-40 degrees outside (I just know ) but the car showed at leat 60degrees outside. What't eh deal w/ taht? Then it'd go and later show 75 when it wasnt even 60...

So what's the deal? Where's the ext. temp sensor at? I know on my W124 it's on the front bumper undre the license plate, but what about on the 2000 W210? thanks!