I need the side brackets for an 03 silverado. my unit is missing them please help if you can. Thanks

What unit? The factory or your AVIC?

My avic is the ones I'm talking about thanks

You need to buy a dash kit, not just the brackets, otherwise you will have a gap around the radio you could throw Skittles through. Try out the Best Kits BKGMK422. It works well, looks good, and the Z1 will flip down without any filing needed.