. . well I had the centre console out to clean everything up and now I am having intermittent problems. The car locks in 'park' and I cannot move it. . . and then the shifter will move [for some reason I have yet to discern] and let me move again. . . and then it will stick in 'park' once again. This is very disconcerting.

On my transmission the interlock mechanism is a plastic key like object at the very end of the shifter arc and I have had it out on a number of occasions. It is about two inches long and really does resemble an old fashioned key. One side of the 'key' is different to the other. I really don't know if I am getting it back into its holder or not. I am going to remove the black part of the console and see if I can find out exactly where it is supposed to slide into its 'lock'.

I suspect I am the author of my own problems here.