My current design has it at 12' wide, 32' long, height unknown. I have designed a swing-arm suspension that preserves the movie interior and exterior while allowing for suspension travel, 4-wheel-drive and 4-wheel steering. Splits in half down the middle, lengthwise, for transportation to and from events. 8-cylinder diesel engine under the front turret feeding an automatic transmission, with a semi differential/ axle just behind the front wheels, which connect to the hubs through the 'swing-arms' which house a chain-drive. Driveshaft goes back to the rear axle just in front of the rear tires, feeding the rear swing-arms. Double coilovers allowing for suspension dampening with hydraulic rams to change the ride height.
My intention is to build a 1/4 scale model, 36" wide x 8' long, with a brushless electric motor. This will showcase the drivetrain, suspension, steering, and separation mechanism and serve as a prototype for the full-scale build. I'll start on it as soon as i get my truck engine rebuilt. Just started tearing it down this afternoon, had to rebuild the engine stand first. Parts are all in, just need to turn wrenches.
I haven't actually gone to a tractor dealer yet, as money has been tight. Since i'm not buying anything immediately, and i hate having people think i'm wasting their time, i want to give the person who helps me $40 or so for their time. Showing up with blueprints in hand should buy me a little respect. I have a sign company and a 24"-wide pen plotter so that will be easy.What are you thinking of using for the tires? They are such a big part of the look of the vehicle, and it seems like they could be a major factor in determining what size the overall build gets scaled to.