If your thinking about adding a aftermarket alarm then let me tell you what an installer here in town did for me. I called Bluebonnet Ford last week inquiring about just adding an external perimeter module to my existing Shelby/Mustang alarm. One that would work with the Top down on my Vert. He gave me the number to Gear Stop a company that does all the contract work for the dealership as far as alarms, tinting, and upgrade to stereos. The guys name there was Randy, been in the business 20+ years. I told him I was interested in a 2 way fob a shock sensor and a perimeter alarm that would work with the top down. Here's what they did, Viper 350r module with 2way communication fob, added perimeter module that covers the outside and inside of the car even with the top down. Shock senor just in case the perimeter fails. Hood sensor, and...........here's the cool part. He left the factory alarm in place and has it controlled by the viper so the tilt sensor also is still in place and functioning. The viper enables and disables the Ford alarm.
459.00 out the door
Money well spent