Okay, let's think this through. If there truly was a tunnel, wouldn't the school staff know and block access to it? Seems like a huge safety risk, so I'm leaning towards it being total bunk.

Let's think logically, driving on the moon could present issues no one's considering—oxygen for the characters, physics of the vehicles... Then again, it's GTA, since when do they care about reality? 🚗🛸