I have an aftermarket alarm setup using the factory key fobs. I have the Viper 5104 1-Way Security and Remote Start System, with a Smart Start module for Android Phones and a digital tilt sensor. I love it. It uses the factory key fobs and all of the buttons are still fully functional, I also lost no functionality in the cars systems such as the buttons on the door handles and trunk lid, or the auto headlights. Three years now no issues once I went to the right place. I had Best Buy do the install on my Gen 1........ what a headache that was, I should have known better. Once I reasearched it well and took it to a reputable shop who deals with high end cars such as Lexus, Audi, Infiniti exct. I have had zero issues. One dealer said they would do the install but qouted me a ridiculous price like $1500 and that didn't even include the digital tilt sensor. Another Infiniti dealer reffered me to the shop where they send their cars for such work and I dealt with them directly for $800. I've gotten so used it especially in the winter I don't know what I'd do without it. I had them install it to work with my factory key fobs so I do not have to carry around two remotes. So I remote start the car by pressing lock twice on the factory key fob and it has the same range you get from the factory fob. The aftermarket Viper remotes work too if I want extra range but since I have the Smart Start on my cell phone I only carry the factory key fobs. Highly recomended for anyone who wants it done. JUST MAKE SURE THE SHOP YOU GO TO HAS EXPERIENCE DEALING WITH CARS THAT HAVE COMPLICATED ELECTRONIC FEATURES SUCH AS OURS. If you can preferably go to someone who you know for a fact has done this type of work on Infiniti's and had good results you should be golden. Even though with time all shops will be decent with this type of work Nowadays you have Ford's, Kia's and Hyundai's that have features like power liftgates and trunks, bluetooth, gps, usb, voice commands. I got into a friends Ford Escape the other day and couldn't believe how many comfort features it had it was pretty decent.