Toyota Avalon grinding noise from rear when in reverse, possibly related to sun shade issue on Toyota Avalon

Some Toyota Avalon owners report experiencing a grinding noise from the rear when in reverse, which may be linked to issues with the rear window sunshade. Problems have been noted with the sunshade getting stuck in the up position and grinding when attempting to lower it, either manually or by shifting into reverse. This issue has also been associated with the failure of the rear third brake light, prompting some owners to remove the fuse. To mitigate the noise, owners are advised to consult the manual for the fuse key and locate the fuse box above the driver side kick panel, which may prevent the sunshade from actuating in reverse. Additionally, properly reinstalling the rear sunshade and ensuring the wiring harness is correctly connected could help resolve the issue. If the grinding noise persists, seeking assistance from a professional mechanic or contacting a Toyota dealership is recommended.