I bought an adaptor from Auto Zone and I could not get the adaptor to insert into the plug all the way. I returned it thinking it was the wrong one. So I went to the Toyota dealership and bought an OEM part and I'm having the same problem. I can insert the adaptor into the plug and it feels like everything is lining up but when I apply pressure to make a snug fit nothing happens. The adaptor is very loose so I know it is not in the plug correctly.
For those of you who have the adaptor, was it difficult to get a snug fit? I don't want to push too hard and damage the plug.
Here's the part# from Toyota.