I've had a 2007 GS350 now for a couple years and the trunk has never seemed to close correctly. If you don't slam it shut, it either won't latch at all or it will latch but won't be completely closed and then open again on it's own. Also, when I hit the trunk release button, it sounds like the latch is under a lot of pressure when it releases the trunk lid. I assumed the car had a soft close motor for lid that was broken, so for a while now I just refused to use the trunk. I finally got tired of not being able to use the trunk, so I ordered a new latch assembly. After replacing the assembly, the trunk is still having the same issues. Am I missing something, or is there a different issue all together?

 

Check "the car care nut" youtube channel, he restored LS430 with the same problem and I think Lexus uses similar assembly. He fixes that with a new part just like yours. After market parts sometimes are worse than a broken OEM Toyota part, so make sure you used the original one. Also your trunk must align with your car body so it might need some body shop alignment.

 

I have the same issue with my 07 GS.
I close the runk and I hear it grab and pull it down then if I wait about 10 seconds I can hear it release. Sooo frustrating. Yours is the first post I have ever seen on this. Everyone else on here complains about it locking and they can't get it open. Mine is it won't stay locked. So I drive around with the dash reminding me the trunk is open. That and when I go over a speed bump or train track it bounces open.
Did you figure out a fix for this? I don't want to start throwing parts and money at it especially since it doesn't sem to be a common problem.