This Bake-O-Glide™ Splash Shield, sold individually, hooks over the handle of your lid when it is raised and protects the aluminium liner from burnt on grease.  It hangs far enough down to protect the hinges of your lid, the trickiest bit to clean. Also useful for cooking pizzas on the floor of the oven - pull them out using the handle!
 
Wash with soapy water or in the dishwasher.