i would check with road angel uk with regards to the road angel not alarming. i had one in the car and i got caught in alloa. the dam thing never went into alarm and when i got pulled over i asked the police to go round the front of the car and aim directly at the angel and ......nothing. turned out there was a fault in it so as you might have guessed i was not best pleased so now even with the road angel "repaired" i dont bother using it as i was relying on it and it let me down so cant trust it.
Now just use the wifes eyes so i can blame her if i get caught next time!!!!!!!!!