I had a similar problem on a trip up in the mountains around Santa Fe. This was only the second day after I got my car back from the shop (door replacement). Every so often, I would hear a "tunk" and the trunk open would flash up on the message center. So I got out to close the truck...

It did it again about one mile down the road when I hit a rough part in the pavement. Pulled over, checked the latch and closed it up again.

About five miles later, it did it AGAIN! By this time, I'm getting pissed and give it a good looking over. And find that the truck light was loose. Every time the lead on the light would touch the metal bracket, the trunk release would fire!

Popping the light into it's socket correctly fixed the problem. But it sure had me worried for a few days!