I broke it, then fixed it.. Check this out if your trunk will not lock when you close it.
I loaded the trunk with stuff and had to bungee it down.. After I emptied my stuff and tried to close the trunk it failed to lock!!!
I checked around the trunk and after closing harder and harder it would finally lock. But I knew that I had broke something.
Anyhow, I found a tiny little spring on the "Latch" that had been plucked out of a retaining spot (this happend when I used the bungee to hook on the "latch" to keep the trunk lowered).
I used a pair of small tweezers to stretch the spring back into place.
Before you take your car to the dealer and they charge you $300 to fix this problem, check this out first you may be able to save some money.