fly in instrument panel

A month after purchasing Prius III a "housefly" appeared inside of the instrument panel. I observed it on and off for around a week, its underside visible when it sat on the inside "glass" of panel. Eventually it disappeared and I assumed it had died and settled to the bottom. Several weeks later I brought car into dealer to have some basic settings changed & to install SAT radio, as they didn't have time when I first picked it up. I told them about the fly. One manager said they'd look into it. They called back to say that they would have to remove the entire front and it would take half a day. I said fine. Then they called back and said this wasn't covered by warranty. I asked how fly got in there, and was told there are several places that a fly could enter. Finding this odd, I called another dealer who said instrument was completely sealed and there must be a problem. I called my dealer and reported this alternate info, and they said they would look into this. Finally, I received another call an hour later, was told that the person who said there were many places a fly could enter was incorrect, but was then also told the fly had actually been sitting on the outside of the 'glass', not inside, and I had been observing an illusion! I didn't know what to say - I needed the car back (by now they'd had it 2 days as the radio took longer than they thought it would; I didn't push the issue - they were giving me the SAT radio and installing it for free, as I'd been told when I purchased it by the salesman that SAT radio was installed, which it wasn't.) I hadn't seen that fly inside or out for weeks by the time I brought it into dealer. Where I live in NE we have very few houseflies, and I've never seen one inside the Prius, then or since. I'm certain there's a dead fly in there where I can't see it. So, are there openings to the instrument panel where a fly could enter, or not? Was the dealer lying to me because they didn't want to hassle with getting into the panel??