what is this peeping noise?

[felinechums]

I live in a ground floor flat and the man in the flat upstairs parks his car outside my bedroom window. Throughout the night, the car makes a loud trilling peep from time to time. Sometimes there is a short time between the peeps and sometimes a long time. It drives me mad, as I can't get to sleep waiting for the next peep. Can anyone tell me please, what is this peep, and is it legal?

[maxi2]

It is probably an over-sensitive car alarm designed to sound when any walks past or approaches the car. These alarms are very antisocial for the reasons you have discovered. I don't know whether or not these are illegal but they ought to be. Let me know how you get on!

[Teddio]

It sounds to me like the low battery indicator on a smoke alarm.

[stewey]

Perhaps the person left their mobile phone in the car?

[mikie_gb]

There is more than likely a fault with the alarm. If it is a regular occurance you should discuss it with the neighbour or if you are not comfortable with that your local council's noise abatement department.