If you have a pushbutton access device you have the keyless entry. If there is a small LED under the ash tray with a little microphone device in the same location you have the keyless alarm activated. If no LED, you still have the alarm wiring in there. They just didn't connect it. Same with the '03s. There's a simple disconnection to activate it by just pulling a connector behind dash assembly (by steering wheel) and VOILA. You got it. If you want to get the LED/Microphone accessory and install it yourself it costs 175.00 from dealer. I bought one(factory original) on ebay for 50.00. There'a link in a not too old post here that shows how to do the disconnection mentioned above. The microphone is a break-glass sensor. You don't need the LED or the sensor but I prefer to have it. I like little lights. The system uses the stock horn for alarming. It's a no-brainer. I'm living proof.