Does anyone in this room know how to add automatic start to a 2005 RL without having to add an additional remote? I would like to use my smartkey or 1 smartkey for both functions, if possible.

 

No idea to be honest. I would find a reputable shop in the area and see what they can do..

 

most likely would be do-able except the range on it will suck... you will only have the range on your OEM keyfob... and does it really help if you are auto-starting your car when you are like 10ft from your car and almost to the door?