The underground parking garage is where the Pacific Courier truck pulls into and parks, where the terrorists then get out and do their various positions to make the heist work. The parking garage is monitored by video cameras, so it is likely that they would have been caught had Karl not killed the security guards prior to this. Argyle winds up getting locked into the parking garage and later knocks Theo out cold after he attempts to unload a getaway ambulance from the back of the truck by raming the ambulance with his limosine. Argyle busts out of the garage later.