I built a small ESP based device which collected Wifi data (mac addresses) enough to use the Google API and plot its course on a map after the event.

It struck me it wouldn't be too hard to use the same device to replay the WiFi data back to the phone to make it think you were on that journey. It would also require shielding to avoid access to GPS and to the real WiFi access points around. Eminently doable though I would think.