I figured it out. Must have hit the push-in button on the signal changer lever by accident. That button cycles through trip computer stuff on the dash, one of them being the "LIMIT --- MPH" setting. Didn't even know that button was there, just got the X5 about 4 weeks ago.

Awntchi - Yes I did install the radio myself. I had the DSP system with navigation so everything is in the back. Had to run the extended eonon harness from the dash to the back. The extended harness runs from the headunit in the dash to the back and plugs into the factory plug that is currently plugged into the radio module near the battery. Then you have to pick up another aftermarket connector to plug back into the radio module (since you unplugged the factory one) and jumper 4 wires, I forgot the exact ones off the top of my head, but at least 2 go the DSP amplifier harness. I have the links to provide more detail on my home computer I can repost for you later.