My 2005 ls430 trunk will not stay close.

 

Does the latch mechanism move when you press the fob or dash button(s)?
Spray the mechanism with some WD-40 if it doesn't move.

 

No it doesn't, I lost my original key and had to get a new one from lexus. I mean I had tow the car to them. They reprogram me a new key. And at some point I realized the car doing weird things when I was close with the key. Now the trunk release just keeps releasing and the gas tank door will not open. I have to unplug the battery for the trunk to close.