The new Ork Warbikes are one of the best miniatures ever created by GW and I'm planning to have an army of them that would but the Ravenwing to shame.

But what about the Warbosses' Bike? Surely any sane warboss would build up his ride to make it bigger and better than his boyz' bikes!

So what kind of monster could you convert to mount your warboss on?

The only ideas i've had is either a quad bike using the space marine bike or a wartrak with the boss on the back (like a chariot)