Finally, I managed to release this addon.
I was going to create some vehicles for them too, but I'm a bad modeller and no one didn't want to help me.
So, if you're interrested to help me with modelling, contact me.
This addon is still beta, meaning there may be bugs on it. All the required files are included with the pack.
Download and have fun!
Edit: Update v.1.0 released. See the readme for more informationScreenshotsDownload here