[Geof]

Not in a car gearbox to my knowledge.

I think you should see if you can find an old burnt out gearmotor at a junk yard; these have wormgear reduction many times.

It is possible to make a worm drive using an ordinary spur gear which has the teeth straight across not at the helix angle of the worm. What you do is mount the worm at an angle so it meshes evenly with the gear.

This arrangement cannot transmit as much torque because the curved worm only make a small area of contact on the straight gear but if it is just a moving stage maybe you do not need much torque.