I use an after market system with mine. Mine did not have a factory security on it though. I had to add a door lock actuator motor into my drivers door. If you look here, you can see what wire needs to be attached in order to disable the factory system if you are going to add an aftermarket system. Kia Sportage Alarm wiring I only added a alarm on mine so I can use keyless entry and remote start.

96 Sportage EX. Automatic. Sold and sadly missed
4" UpYourKia lift

89 Ram 50 4x4. 4D56T swap in progress
30x9.5x15 Pirelli Scorpion M/T on Toyota steel wheels

06 VW Touareg V10 TDI.