I experienced the same issue with my 164Q this evening. This time I was just showing the car to a friend. I tried to start the car and the key would turn, but the engine would not start. I noticed a small rectangular red light in the instrument panel above the top of the car diagram blinking once a second or so. The owner's manual stated that this indicates that the antitheft system in active. I do not know how it became active. I did not receive a remote transmitter with the car. The PO told me that he did not get the remote with the vehicle (and he was the original owner). I did notice this light blinking when driving the car a few days ago, but did not think much of it then. After a closing and locking the vehicle and opening and closing the trunk lid a couple of times the car did start. It started like normal with no indication of a problem. I turned the motor off and was able to restart the car two more times without issue. On the third try it would not start again. I can't figure out what is exactly going on. Previously, I had been able to start the car up without an issue about ten times over the last couple of weeks. I'd appreciate any help with this issue. Thanks.