The Premium Package for $1550 which includes a host of other thing includes the remote start. I guess you didn't get that in your vehicle?
Here's what comes with the premium package: Thirteen Bose® speakers; Audio system includes in-dash DVD; DVD/VCD; Entertainment display screen located in front includes DVD; Bluetooth® includes music streaming; Memorized adjustment: includes two driver settings, door mirror position and steering wheel position; Smart card/smart key with memory seat and radio settings on memory steering wheel; Driver front seat memorized height, power lumbar and memorized tilt; Steering wheel; Driver and passenger door mirrors; Remote engine starter
If you don't have those features, then you don't have the package which to me would mean you either have to now pay up for Infiniti's remote start 'a la cart' or go aftermarket.