I have a 2009 Honda Accord EX 4 cylinder. Nobody had driven my car in 2 days, all windows were closed including the roof and the car was locked. On day 3 I left my driveway in another car and I noticed as we were pulling out that my moonroof and all windows were open. How did this happen? My remote doesn't even open my windows or moonroof. My doors were all locked also. Who opened my entire car without even being near it ?
According to the 2009 Honda Accord Owner's Manual, your car is capable of opening the windows and moonroof with the remote transmitter.
This is most likely the cause. The may have been pressed for accidentally in a fashion that triggered this feature.
Did you have the keys/remote in your pocket? Some cars (e.g. my VW Golf VR6) can open windows etc if you hold down the open button for several seconds. Did kids play with remote?