Thorton Mackinaw "Demiurge"

The "Demiurge" is a heavily customized variant of the Mackinaw, a vehicle manufactured by Thorton in.

Acquisition
Given to V by Polyhistor after solving the FF:06:B5 mystery. The coordinates for the mattress are obtained by completing the hidden maze in the Arasaka Tower 3D arcade game. Standing still on the mattress for ~50-60 minutes of in-game time (7-8 minutes real time) will trigger a cutscene after which you will be woken up by Polyhistor, who will disappear afterwards, leaving the vehicle.

It is possible to bypass all these steps and just venture to the mattress after 04:00 AM in-game time.