This next riddle will revolve around the Batmobile's Battle Mode winch, so wait for Riddler to lower the water, then attach the winch and lower your vehicle to right above the spinning drills. You should notice an unusual wall pattern, which is what we're going to use to solve this riddle. Rest the Batmobile on it and move your left stick to the right, until the Batmobile is sitting on the "Reserved" marker.
If you look behind you, you should see an opening in the wall, so eject from the Batmobile and glide into it to find a switch to lower the water some more. You will be able to grapple to the Batmobile from the entrance to this small room, so do that and bring it back to the top, then go towards the "2" marker, where there's another winch. Lower yourself to the second level and move the left stick to the left this time to find another "Parking Reserved" space. Look across from you once again to find a weak wall, so blast it open and glide into the tunnel, making sure to bypass the electrified panels right by the entrance.
Hit the switch on the ground and some of Riddler's robots will appear, so make short work of them and get back to the Batmobile (the panels are safe now). You may think you just need to go to the spot marked with a "3" and do the same thing, but you have one more thing to do before that. Return to the "1" drop and lower to the second level, then rotate the ring to rest on top of the marked spot (this one doesn't click into place like the others, so try not to hit the drills).
What this does is create a path on the "3" spot to allow you to get to the bottom. So, go do that and glide to the opening that's across from you to find one more switch on the floor. The only problem is that this triggers two sentry turrets to spawn in the exit, so switch to the Batmobile via remote control and destroy them. Glide to the platform in the middle and stand on the switch to reveal the same glass cases puzzle as you've done before. Switch to Catwoman, grab the key, then you'll be finished with this riddle.
