I have a new G30 and the TCB has a programming fault and the SOS emergency malfunction light come on the instrument cluster,,,,so you have to remove the rear cover for the 3rd brake light and you must lower the headliner. Here you can see the old TCB mounted on the roof,,,,it clips onto the shark fin which is on roof of the car. Here is the new  TCB you can see where the pocket screw is lifting up the lock that clips it into the shark fin ,,,,on the left side you see lid open inside is battery’s,,,,you have to switch over the battery from the old TCB to the new TCB,,,,if you don’t you will be hating life and will have to lower down the headliner again.,,,then the fun part is programm and encode the TCB.