Cracked fiberglass on inside of doors please help.

[purpleone]

Hi I am new to this forum and have been told that there is a wealth of good information out there from you guys! Can anyone help? Has anyone suffered this on their elise and what is the best way of getting it fixed. Also why does it happen? Has someone just closing the doors to hard or is this a common fault. The croacks are just very small but would prefere is it was sorted before it got any worse. I have not long owned the car so just getting used to it.