1st of all - Kudo's to Andy for running the pants of his car an getting TTOD!!!
As for suggestions... you have gotten some very good one - though I have never done the crouching thing - though it makes sense.
I am terrible at drawing maps so I forego what Andy does - and often I am okay without a map - but this past Saturday I wish I had one and had his discipline to use it the way he describes.
My #1 observation is that I think many autocrossers make the mistake of stop getting instruction - we think we got it etc... I believe it was last year when I gave a Bill Benz a ride in my blue 914 - he commented that I had lost the smoothness that had impressed him when I was driving in Bi. I thought I was smooth - but when I reflected on the run I realized I had lost an element that had made me competitive in Bi. This was after 20 years of autocrossing... I still learned something...
With that in mind - let's remember that the instruction is free! In fact there were instructors with very little to do this past Saturday. We would have been happy to ride and give suggestions. Get suggestions and ideas from different folks... one of them may give you the tip that allows all the cards to fall in place.
One other suggestion - I try to pre-visualize the course as I pull up in line... watch the cars that are running in front of you... remind yourself where the course goes and what you planned to do different on this run... not just one corner, but all of the areas you wanted to improve upon, etc...
When you run is done... immediately self-critique yourself... reflect back on what worked and what didn't, what you want to try differently, etc...
I have heard the comparison that Autocrossing is like Golf (!) - a lot of it is technique, comfort in controlling the tools, but a large portion is mental... confidence and staying calm and being able to reflect on what you did and work on making the improvements required. Re-read Andy's post and I believe you will see the mental part of the equation was very significant in his response... and has nothing to do with engines, and tires and suspension.
And again... do not ever hesitate to ask for instruction... there are plenty of driver/instructors that will sit with you and give you ideas, ride in the passenger seat etc...
Sorry for the long post...
Steve