07 rear latch problem

[jonny07]

I have a 2007 SR5. This winter I have had a problem arise with the latch on the rear cargo door. When you try to open it it makes the sound like it is disengaging but it doesn't let go. It also stopped doing the "auto shut" (unsure if related). This all started after I took the vehicle through the car wash. At first I assumed it was frozen. But after thawing it out that was not the case. Rust maybe? Or do I need to buy a new latch mechanism?