good question.....we has been experience before.it will be depend to the installer how there do it. but the correct way is arm the alarm then the engine still running after just switch off by the timer.
i wish to find out, with our hot weather esp during afternoon, whats your ride water temp and oil temp? both water n oil, for mine, are da same reading, for eg, if my water temp is at 80c den my oil wil b around that...