At the time (end of year 1999), I was into pneumatic cranes. So I decided to model a European parking enforcement tow truck (since they use a crane to lift illegally parked cars).

The model has three solid axles with suspension. No driving motors. Driving/steering is done by hand.

The model also includes a pneumatic rear car lift, powered stabilizer legs, a powered compressor, and a powered winch.

This is the basic chassis. You can see the front solid axle with steering and suspension. The front is attached to the back through the stabilizer structure.
You can see the air tanks and the turntable for the crane. I used four shock absorbers per rear axle.
The air compressor is partly visible inside the chassis, just in front of the first rear axle.
A nice view of the front axle. Four shock absorbers ended up being a bit firm.
The cab is now done. See the cable spooled up under the turntable.
The motor powering the winch can be seen behind the air tank.
The base of the crane. Since it should be capable of lifting a car, three air rams raise/lower it. Notice the micromotor to rotate the turntable.
Here you can see the rear lift mechanism. It is raised/lowered by three air rams. The black hinge at the end is from the tow truck (as will be the wheel holders for the towed car).
General view of the truck. Just missing the top of the crane and the flatbed.
Truck at work! The crane has the boom extended. The strings (belts on the real truck) have to be looped around the car manually.
Car is off the ground. Notice the suspension at work, even with the stabilizer legs out.
Another shot of the loading process. A couple more shots of the loading are below.

Car is loaded. Now place a second in tow. First pull it with the winch (after lowering the car lift).
When the car is in the holder, simply lift it off the ground. Finally, a few more action shots below.