For some reason my trunk opens on its own. Usually when I pressed the clicker once to open it, only the drivers door would open. Now the Driver and the Hatch back open. The strange thing is that it doesn't happen all the time! so I have been using the key. But every time I get out I have to make sure that it's locked because sometimes, out of nowhere it opens.
I have no clue, but my gut says it may be the clickers battery!!???
Start by replacing your keyfob's battery and see if that helps.
You can download a copy of your vehicle's owner's manual at this link:
http://www.chrysler.com/carryover/download/pdf/manuals/2005_JR27_Sebring_Convertible.pdf Information related to your keyfob's operation begins on page 17.
If replacing the battery does not solve the issue, it's possible you may need to replace your keyfob. Given the age of your fob, it's possible that it could need to be reprogrammed or may have developed a short.
If that doesn't help things, please find an AskPatty Certified Repair Shop at http://www.askpatty.com/search/?type=all&m=30&q=&keyword= and they can help you diagnose and repair the problem.