This is a tough one, because the Soldiers are in initial training status. The rules are different. This could be considered the same as taking the Soldier’s cell phone during basic training.
What does the Regulation Say?
TRADOC Reg 350-6, Table 2-1 covers privileges during BCT and AIT. Except for the allowance of OSUT Soldiers during graduation day and Family Day can RIDE in a POV or rental with family members, only Soldiers in training from week 21 on are allowed to drive or ride in a POV or rental. Even if the Soldier is in week 21 or farther, the driving privilege is at the discretion of the commander. So, I can see where the command would have AIT Soldiers park in a certain parking lot and turn over the keys to the car. This would take a SJA or Judge to determine if this is legal. My personal opinion, is that it is legal, but I may be wrong. I would also think that if all the units are doing this, then it has been looked at already.