If the aircraft title lines aren't changed, making the AI MD-80 flyable won't change the AI traffic. But I think you may be disappointed when you see that model up close. There's almost no detail.
Go to
www.flightsim.com and register if you haven't been there already. (Do the free registration - you don't have to pay...) Then go to the File Search page and click on the
Advanced Search at the top. Select FS2004 Jetliners, then enter
Eric Cantu into the first search field. Then check the second box that says
"Aircraft base model from original designer" and hit the search button. Toward the bottom of the next page and more on the one after that, you'll find just about every variant of that airframe you could want.
Sorry if all this sounds a little basic, but I'm guessing you're new to FS. It's just the teacher in me coming out! I've owned FS9 since Dec, '03 and I'm still adding, removing, tweaking, fiddling, and everything else!