I’ve had repeated problems with starting. After replacing the battery, starter and ignition key switch, the only remaining component in the system is the transmission range sensor. This vehicle has no starter relay – it is built into the starter. Incidentally, I also found that the 10A starter fuse is completely unused in this car. Pulling the fuse does absolutely nothing to the starting system. The range sensor is an electrical switch that sits on top of the transmission where the shift level cable is attached. It rotates with the transmission shaft, sensing whether the transmission is in park, drive, neutral etc.. The neutral safety switch closes only when the transmission is in park or neutral, allowing the car to start only under these conditions.
The range sensor is cheap ($35) and is easy to replace. After removing the air intake duct, the sensor is easily accessible from the top. The shift cable has to be detached from the transmission shaft using a 21mm socket. The sensor itself is only held down by two hex screws.