This badboy is based on the W900L Flat Top by WalrusAircrafts.
It's a replica of the Kenworth W900L, which is a very popular conventional truck with classic style and modern technology.

In over a week of work I have equipped it with a grill guard, tractor tyres, a studio sleeper cabin, a heavy duty 5th wheel coupling which looks more scale, two turbos, a new trailer and some other small changes on the design. Also I made it symmetrical, as chassis and body were asymmetrical in the base design (probably because the cockpit everything was mirrored around wasn't centered). In this version I sacrificed a lot of details and the interior to reduce part count and increase performance. I still tried to maintain the scale look.

The trailer I made has a special purpose, which is hijacking minions (convoy AA Tanks) which are leading a convoy to make the whole convoy follow you. The difficulty with this is that convoy vehicles disable themselves when they lose ground contact for 10 seconds, so I had to come up with a way to hijack a vehicle without lifting it off the ground. Because of this, the trailer has no floor, it just has sidewalls and a ramp which can be lowered and raised.

I upscaled the truck to have 1.5 times the intitial size, otherwise the trailer would look very big compared to the truck.

To help with handling the truck in different situations and to increase awareness, there are a lot of cameras on the truck. One of them is facing out of the back of the cabin and is supposed to help maneuvering the truck under the trailer. Another one is placed right behind the coupling, so you can see the coupling work and also to find out if you're close enough to couple the trailer. A camera sitting on the trailer and facing backwards will help you positioning the truck right infront of a convoy vehicle.

Controls:
AG1 + VTOL: lower/raise the trailer legs
AG2: activate lights
AG3: activate reversing lights
AG7: power rear axle with an additonal 150 HP engine
Trim: lower/raise trailer ramp (I recommend to raise the ramp fully for driving until you are infront of a convoy)
LandingGear: engage/disengage coupling jaws
Brake: activate wheel brakes and brake lights
Pitch: throttle forwards/backwards
Roll: steering left/right

How to's:

Coupling:
Switch to the camera facing out of the rear of the cabin, make sure the coupling is open and the legs of the trailer are lowered. Drive backwards slowly and aim at the center of the trailer. When the trailer covers the coupling, switch to the camera behind the coupling and close the coupling when the kingpin of the trailer is inside it. Now just raise the legs of the trailer and you're good to go.

De-coupling:
Hold the brakes to park the truck, lower the legs of the trailer and open the coupling. Release the brakes and drive off.

Hijacking:
Find a convoy and drive infront of the leading vehicle. Lower the ramp and switch to the trailer camera, then line up with the vehicle. When the convoy is driving in a straight line and you have lined up the trailer with the vehicle, hit the brakes until you reach 20-25 MPH. Wait for the vehicle to catch up and drive into the trailer, then raise the ramp. Now is a good time to activate the rear axle drive with the additional 150 HP. Drive wherever you want and the convoy will follow you.

If you want to get rid of the vehicle in your trailer, just lower the ramp again and go full throttle, it should slide out of the back then.

Feedback and suggestions are appreciated!
Have fun! :D