I have an 05 manual that I've had for about 2 months now and ever since I got it the trunk will open while the car is locked. The alarm will sounds but what's the point of locking the car if someone could still get it in? Is the normal on every crossfire or just mine?

 

The locks are pneumatic, perhaps the hose has fallen off it's connection with the pump or the lock.

In the SRT section, you can download the service manual and start investigating this. The Pump is on the passenger side behind the stop/tail/turn light assembly. Depening on "Coupe or Roadster", the process of getting to the pump varies.

Same goes for the lock, to get to it in the Roadster is easy, but I've never owned a coupe so I don't know about how to get to it on those

Now that I think about it, I almost remember something about the lock giving trouble on the Coupes before. Try putting "lid lock" or "trunk lock" in the search box here and see what you get.

 

Look inside the rubber boot on the passenger side that goes between the hatch and the body at the top.
If you can hear a hissing noise from that area you have found the problem, a broken hose.

 

I had the same problem with my coupe, one hose had fallen of the connector of the pump.

The passengerdoor and trunk would not close or open. Also the pump will go on for a few more seconds and then shuts off and make a strange sound.
I probably loosend the hose when i was trying to get a bit more length on the cdplayer wire.
My fix was just reconnecting to hose with the pump.

Good luck with the fix, hope its as easy as mine was.