Just about to return the car and then I lost the car key

I scheduled to return my 2011 Q7 on 7/5, and then the car key is nowhere to be found yesterday. That's the only key for my car which is in danger of being towed away tomorrow(parked in front of a leasing office).

Since I just need to open the car and turn on the engine to drive to the closest dealer, what's the simplest solution for it?

Thanks!

Just about to return the car and then I lost the car key