if you getting an alarm, i would stay away from factory alarms. they are easier to install but aftermarket alarms allow you to add additional sensors(motion sensors, glass break, shock sensors). DEI(VIPER, CLIFFORD, etc.) alarms are some of the better quality alarms. as for the pager alarms, i have one and i like it. they cost a bit more, but it gives you a better sense of what is going on with your car.