Ok, let's assume that by some miracle, the police actually find the car, like an above poster said, it will likely be towed to an impound yard...
You will then be called to come inventory the vehicle to declare if any items are missing. They may inventory it upon discovery just to cover their own asses, but that would be it.... But, they have no way of knowing what contents are yours, and what were left there by the thief, nor can they know what of your property you may have had in there before the theft.
(Hey! My 1965 Gibson LesPaul is missing!!!)