so this is pretty funny...
If you know someone has a mechano-hog and they are in the process of casting it. Spam click them until it spawns. If you are fast enough you will steal the passenger seat of the hog even if you are not lgrouped to the person.
This will either force the person to ride you around or get out themselves to remount it. In which case you can just do this again 
Remember you gotta do it AS they are spawning it because as soon as they get on it, you will not be able to ride shotgun unless you are linked to the driver.
This also works with the Grand Black War Mammoth and the Grand Ice Mammoth. It does not work with the Tundra due to the fact that when the driver spawns the mount, the 2 vendors are already taking up the 2 seats.
by bubbajackson