Team, we've been debating getting a remote starter for our 05 TL however, we'd like to keep the original remote with it's present functions.

I realize that we'd have limited distance for starting the car but, is there anything preventing this from happening? I'm in Central Jersey, any reputable shops to have the work done? One place told me they'd need me to bring a spare key and they can make it happen. Key's cost $65.00 @ the dealer, is the spare key needed for a remote start application?