What's the 2010 Audi A4 windshield wipers size?

You're going to have two separate sized wiper blades on Your 2010 AudiA4's windshield: a 24 inch one over the driver's side, and a 20 inch one on the passenger's. You can typically pick up a set of TRICO brand blades that contain both needed wipers for around $22. These come with an installation guide in the package, but You really don't need it: Basically, You can just unhook the existing ones and hook the new ones --- it's pretty simple. It's a good idea to keep up on Your wipers; it's a safety hazard to have these fly off in a storm, or be in a state of disrepair such they don't remove water in a heavy downpour, and You crash into a car because You can't see anything. No, I'm not going to let her live that one down!