im about to take the plunge and install an alarm into my 200sx, its a Clifford Matrix RSIII, now the question is, since i have a keyless entry, could i wire up the factory alarm arm/disarm wire to the lock and unlock wire on the alarm or should i hook up a relay to trigger the disarm of the factory alarm?

Check out this forum that specializes in the topic you are posting about. www.the12volt.com

good luck.

Start here... It took me about an hour to install an alarm into my NX.. I removed the plastic cover under the steering wheel and the metal support which made it VERY easy to get to all the wires needed.
http://www.commandocaralarms.com/wiringsearch.asp

You could wire it that way using the lock wires (from the alarm) on the alarm arm & alarm disarrm wires (in the car) as long as when you test the wires in the car they open and close the doors. If not I don't think you need to use relays. There should be a factory alarm disarm wire (on the alarm). I believe it is Light Green/Black.

yea there is a factory disarm wire but it also says to use a relay to wire it up thats why i wanna do it my way

weird thing on my 200sx the factory alarm only turns on when i lock the door from the inside. so i tried installing it normally without hooking up the factory alarm disarm and I was fine. Btw I also installed a remote start on my 5speed. DEI Python 990