If you use a +12 Volt direct from the battery (not switched) you could create what you are looking for with an extra relay.

The OPT output activates a relay, that relay activates the coil of another realy and that realy latches itself with its own contact, being fed from the battery directly and with another contact (on the same relay) you activate a beeper, also directly fed from the battery.

To reset you hide a breaker switch somewhere.

Something like this:


I would not run the shifter beeper itself directly from the battery, I don't know how much amps it draws, but you might end up with a dead battery if you don't drive it for a while.

 

Well, cant I directly connect it to the battery but have an off and on switch so that it wont drain the battery. I have a similar setup since i have a tv and dvd player in the car and if I didnt have it with the kill swtich, it would drain the battery within 4 days if I didnt turn on the car.

 

The shift beeper itself draws between 10 and 20 ma (.02 amps) so it wouldn't kill your battery anytime soon. The module will not latch the output at all - as soon as the rpm drops below the set value the output turns off.

You can't connect the air horns directly to the shift beeper module as it can only handle about 1/2 amp, so you'd have to use a relay, and if you're using a relay you can of course wire it to latch itself and have a hidden reset switch.

But, what you need to think about are the "what if" scenarios. If you make it latch and not turn off until YOU reset it (even if ignition is turned off) then what's likely to happen? "They" will either let it run your battery dead or they'll cut the wire to the sounder/horn. We've already defined "they" as low-life joy-riding ice-holes so they're likely to do whatever it takes to cover up their deeds.

Or, what if "they" aren't low-life ice-holes but simply accidentally hit 5,000 rpm one time and then can't reach you to get it turned off?