the little truck i drive at work has an external reversing beeper we had to put fibrous adhesive tape over to tone it down,,it was the beeper from hell!,,trouble is it also has a quieter one factory fitted behind the dash in the cab some where,,i cant bloody find it,i even brought a decent flash light in from home and had the beeper activated,the fuse stops both of them so thats not an option,its fkcing annoying,,ill kill it one day when i get my hands on it,you can always hook you oil switch to your ignition,so itll take a bit of a crank to fire up but kill the engine if the oil pressure goes nil,lots of late cars have this wired to the fuel pump,,i dont like it,the idea is in a crash the fuel pump stops so long as the engine stalls.