After driving the car for more than a couple of hours continuously, the trunk latch will not release as it should when the car is not locked. It acts as though the car is locked, that is, there is no feeling in the actuating tab. The trunk opens fine if I use either the inside relaese of the key fob. The dealer has installed 3 new trunk latch mechanisms. This last one seems better, but the problem still persists. It is better in that I drove the car for four 1.5 hour segments over the weekend and the trunk worked after three of them. In daily driving where the car is driven a half hour or so at a time, the latch works fine. It definitely seems that continuous run time and or highway speed triggers the problem. Or maybe, a loaded trunk? Naturally, the dealer says this is unheard of and I think the only reason he believes me is that we didn't need to get into the trunk when we returned from a long drive one time, so we left it until the next day and showed the service writer in person. Any suggestions would be much appreciated.