I bought a 2nd hand furby today... when i put it in reverse... a bleeper from the rear of the car starts... it bleeps pretty much every second.. however this doesnt change even when obstacles are RIGHT behind the car.... at times the bleeper changes tone.. (sort of as if the battery is running out on it)....

im wondering if this is a faulty reverse parking assistant, or just a crazy bleeper?

*note there are no visible sensors in the tail of the car which you would usually find with a reverse park system

You can I believe get reversing light bulbs with a beeper built in so that you can do dustcart impressions when you are reversing. Might be worth having a wee look at the rear light clusters to see if the reversing bulbs look any different to normal? You could try having a look around the boot, under the carpets, in the spare wheel recess etc. for any suspicious after market wiring?