That's a tough one without some more info. First, we need to find out what vehicle it came out of. The new Ex's have two screws on the bottom of the radio and don't use the Ford keys. If it came from a Ranger, Superduty, or Excursion you might be safe. Secondly, we need to determine what kind of plugs your Ex has for it's radio. Two flat plugs, no. One flat plug, one square plug, no. One square plug that looks like it could plug into the back of that new radio, possibly. I say possibly because this new radio may need to be used with a factory amp to work.
One thing to consider, though, is that you can get a very nice aftermarket MP3 player for $300 and Metra's kit for the 99 Ex's does not look that bad with the right radio.
