Here’s a video showing NXTLiftBoy latest project. Here’re a few details I got from him:

About the model:
This is the LEGO alternate model for set 8285 tow truck, but it is enhanced by including a NXT brick and 3 motors for remotely driving,steering and (de)coupling the trailer by a wireless gamepad.

The gamepad and some Java programming allow for proportional control. It is not so hard to control this model. Picking up a trailer however requires high-precision maneuvering because the trailer pin must engage in the right hole.

I applied your idea to convert rotation in translation with the worm sliding an axis with bushings, thanks for that idea:)

You can find still further info and photos at MOCpages.