See Ford Status.Report Card and Ask Ford Analyst, the will tell you the reason,
The confidence Ford has on your Company is shown in their report Card system of Supplier Rating, see your Score there and if you are in red Status

, sure enough this is the reason of the request more Documents.
Level 1, full confidence.
Level 3. Less confidence,
More, A problem, but do not warry at the end the price is an important fact to mantain a Supplier even with a bad performance
