This all has ocurred since I downloaded the full gsx installer as recommended and I did a vehicle update as well just in case.
I'm sorry, but I cannot replicate this, and the only possible reason for a missing pushback vehicle, is that you haven't installed the full GSX installer. Maybe you downloaded it, but you have installed something else, maybe another older download you had in the same folder, which has a similar name.
- Delete ALL your GSX installers in your downloads folder.
- Download the latest installer again, and be sure you have only one copy of it.
- Install the full installer, and NOTHING ELSE. It contains *everything* and it doesn't need the vehicles update.