Didn't read everything, but
- Opening the front door with a key
- Opening the hood/bonnet with the latch in the leg area and
- Attaching a charger or an external battery (e.g. http://amzn.to/22P1VaX) to the connectors under the hood (http://bit.ly/22P2kdI - different car, same connectors)
isn't an option for you to get into the trunk?
Best regards
Mick