I bought this mod about 8 months ago and have had it installed for six months. It is working just fine.
A couple of answers to above questions
1/ the old key fob does
get disassembled but nothing is damaged. It is fully reversible
2/ the battery is not needed in the old remote for the chip to be read by the old lock cylinder.
3/ the physical key does not have to be cut. The blade is removed from the old remote and not CUT and is inserted and left "on" with a cover over it so you cannot see it is even there.
4/ the start button starts the car when you push and hold it. My car does not require the brake pedal to be pushed but some years do and this is accommodated with the kit.
5/ the accessory mode comes on by simply pushing start for a moment and not holding it till it starts.
6/ when you walk away from the car the locks auto lock and when you return they auto unlock
7/ if your battery were to die then you have several options - 1/ call AAA and they will get it open in 2 min, 2/ keep your old 2nd key in a hidden magnetic box somewhere on the car to unlock it manually, 3/ go to a locksmith and have the new remotes backup key cut to work as I did
Let me know if you have any other questions
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