Just an idea... I had a 2008 Roadster once. There was a plastic ring around the ignition switch. This ring was a component of the immobilizer. It was not stable, but could be moved back and forth. I think it had a function to the inductive ignition key.
If this is the case with your car, then try moving or turning this ring back and forth, just a little bit. And try to start in between. This had the effect that the car could start again immediately.
