Hi,
Haven't had the problem of the alarm going off but the rearwindow opening by itself I've gone through, back in november 2001, the car was bought or let's say delivered january 9th in 2001, on one morning after a night being parked outside I saw my rearwindow completely lowered, as it had rained that night (fortunately the wind blew from the other side) I got rain in the boot but not too bad. Called the garage and they told me they had a couple of these problems before, they replaced the CCU (central control unit I guess ?) and since no problemp. First they were insinuating I kept the "door open" key on the fob too long pressed which also makes the window go down but when I told them it had rained inside they no longer objected and swopped the computer.