If I were trying to go full on Sherlock Holmes, I would layer some paper towels in there to try to figure out where it's happening.
Take everything out and put a paper towel in the bottom of the drawer.
Then make a burrito out of the utensils using a paper towel as the tortilla.
Then put another one over the top of the drawer just to overdo it a little.
After your next drive you'll be able to see if it's coming from the top of the drawer, the utensils themselves, or the bottom of the drawer.
If you have the patience, you could leave it that way for a while to see if the powder is a function of the miles you've driven or just the passing of time.