I have to say thats the first time i've seen someone clear out a system without cutting wires.
I used to work in the auto industry and I have never seen someone who has popped a window to get in take the time to remove things properly. They go with wire and bolt cutters through everything and pull it out quick because the popped window is a dead giveaway for a break in.
It really sounds like someone was aware you were returning the vehicle, or was aware you'd be gone all day. Like someone with an Aviator maybe?
__________________
|