Short answer is no. You would have to replace a lot more than just the headunit and it would be prohibitively expensive and that's if you can find someone to do the work for you. The dealer won't even consider it.
The XL unit uses a different controller for one, some of the navigation hardware, but the biggest hurdle is that the wiring harnesses are all car-specific. There are no "one size fits all" harnesses. They are custom for each car based on factory equipment. That makes it very hard to retrofit certain options.