I recently had my key rplaced by audi because it was defective. Now i went over to a friend tonight and i parked it on a main road and i locked it..... a while later my alarm was going off so i went and unlocked it and locked it.
Same again a while later and also a few times, straight away im thinking provlems with the key fob etc (Under audi parts warranty)
but then i thought i wonder if its cars going past, they would be passing about 1ft-2ft away at about 20-40 mph. I have locked my car now its in an underground carpark im leaving it until 10pm to see if it goes off again, hopefully its the cars going past.