[908/930]

Congratulations on the 930, like the colour. I have never had a key get stuck like this but I would try to gently play with the key for a while and hopefully it will pull out, I assume you have a key that was used regularly. Hopefully somebody knows an easier way but I think it is possible to reach the starter and start by making contact between the main battery cable and solenoid terminal, it is a long way up beside the transmission though.

EDIT There is a possibility of exposing the starter wire from under the ignition switch and making a jumper wire to go from the cigarette lighter and piercing the starter solenoid wire, yellow I think.