1)Trying replace them myself using used parts (I will need to tow the car later to a dealer to reprogram immobilizer). I have been looking online and found out that they are rarely sold on their own but usually with the whole streering columns. The columns are really specific - MT or AT, w/o cruize or w cruize, w/o fogs or w fogs. But how specific is the lock housing with the lock cylinder, pin actuator and the switch and how specific is the immobilizer?

2)I asked at a dealership if they can reprogram used immobilizers. They told me sometimes there are problems with it but they did not tell how likely is this "sometime" to happen. Does any body here know?

3)The old immobilizer has the antenna loop broken off. There were attempts to start the car without that loop. If I glue the loop back to immobilizer box and properly solder thing copper wires in it should the immobilizer start to work again theoretically? Or it gets re-set or blocked when this kind of mechanical damage happens to it? Or it is likely to have software glitch in this kind of situation? It is tricky to solder the wires back together so i want to know whether it is worth the attempt.

Thank you!