Can't hurt to put an order together, be prepared to pay for it and then ask for a 10% deal or what ever you think you can get away with. You have to be ready to pony up if they agree to give you the deal though and I would imagine that you would need to be ordering a little more than say a replacement cabin air filter to make it worth their while.
What's the worst case scenario ? They say "no."
The other thing to do is go to the sites you want to get stuff from and get on their email list; I did that with Performance Parts and less than a week later I got a 15% coupon that I was able to use for what I needed at the time.