I have heard an auto car alarm go off many times in parking lots an other gathering places. It seems no one including my self will even look up when one goes off...
I imagine the same will go for the RV ALARM. The camp ground will probably ask you to leave for disturbing other campers...
Maybe the noise will drive away the intruder or maybe not... We would hear auto alarms go off all the time when at a fireworks display on the 4th of July...
In the RV CASE perhaps this will happen when parked at a camp ground or Parking lot somewhere and no one around. Who is going to show up to help...
Just like having lights come on when the motion detectors detects movement. You will probably find a note left by the intruder saying "Thanks for the added lights - helped alot"
To me localized ALARMS may not be much help for the cost involved... Silent alarms would be the way I would go. The downside to this is the false alarms - be prepared to pay the POLICE for their services if they are involved...
Just some thoughts here.
Roy Ken