Hi, the back door on the drivers side of our 307 wouldn't open and we had to get peugeot to open it from the inside by taking the door card off. I since found out that this is a common problem and had to have a new lock fitted as it would not release itself after being locked (i think it was called an "actuator"). All in all it cost £200 for the parts and labour as i got both rear locks done at the same time as the other lock was on it's way out and the cost to have the second one done wasn't much more.
Hope you have better luck with yours. :thumb: