Most likely came with the stereo / 6-CD unit. It is/was a POS and most people replaced them with NAV units when the CD player broke. The factory navigation option was very, very rare and usually only showed up on special order vehicles where someone spec'd one out and ordered it. Navigation was a more common option on the Lincoln Navigators. Today the aftermarket NAV unit choices are much more appealing and I believe far superior to anything you could've gotten from the factory units of the period. Nobody uses CD's anymore and most aftermarket units come with Apple or Android phone compatibility, WiFi, and dozens of apps and traffic reporting to entertain you. I think the Micro SD card music storage has replaced the CD options. The space the CD slot took up is now replaced with a bigger viewing screen. Crutchfield will get you setup for a great installation, and most options are plug-n-play. You can just tuck the GPS antenna puck up onto the crossbeam behind the head unit and it will see all the satellites just fine. Oh, and yes, there is an add on harness that connects the rear DVD player to the head unit ( Crutchfield can send it to you...). You lose rear seat control function though, but who cares. Your overhead DVD player is not made any more. Mine failed and I had to get a later version and make a harness to go from the '03s 12 pin plug, to the later version's 20 pin plug, and went to IR headphones as well.
But to answer your question, this is the head unit the Expy came with from the factory (junk)....