I think one of the most important things that came out of Greta's program tonight was the fact that LE is searching and their search is based on evidence found in the car.
We know that LE has mentioned three things in the trunk of the car - hair strands consistent with the length and color of Caylee's, a stain, and dirt.
But, LE hasn't mentioned "other evidence" found in the car. What other evidence was found in the car? Receipts for toll roads? Receipts for items that would be unusual for a 22-year-old woman to purchase, like a shovel and tarp from a hardware store? Gasoline receipts for somewhere outside Orlando?
I'm hopeful there were items in the car that have allowed LE to pinpoint a specific area in which to search.