Hi coppershot. As I mentioned earlier, I haven't tried PAI myself. Full details of the PAI installation should be explained on their site. This involves downloading special AI versions of various airliners in different airline logos. I think that traffic tracks for the airlines are included in the packages or available separately.
If you want to stick with the default aircraft I think the only way would be to add your own traffic tracks with TTools. Check out the AFCAD & TTools forum for more details.
PS. If you look on the PAI Official Files/Special Packages page there's a file named FS2002 Default Commercial Traffic Installer.
http://www.projectai.com/packages/installer.phpI don't know exactly what it does so you would have to try it yourself. I think you might also need the PAI Installer.