You could connect two diodes to the 'on' outputs, and connect them to to the trigger of a relay.
Then use the NC connection in the relay to power the buzzer.
When the switch is in either of the on positions, the relay will be triggered, turning the buzzer off.
Make sure relay is powered by ignition live though
The Lc1 and LC2 use different sensors, so be aware of that, I forget the nomenclature, but it is clear when you start looking as the plugs are different.
If it works and gives a reading then it will be fine, I've certainly had one in a box for 5 years and it worked fine on first switch on, just remember to calibrate it in free air.
Well, it is a quattro.... Don't think I haven't though about building a 5 cylinder turbo independent suspension buggy...
FWIW it had hydro boost from factory, but too expensive to fix when it went wrong, so runs a normal servo now.