Is it leaking inside of the 3rd brake light housing, or is it just leaking into the interior from the gasket?
If just the gasket, here's one on amazon that I bought and it was a perfect fit: https://www.amazon.com/gp/product/B07H3RTDSW/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&th=1
If you have water inside of the 3rd brake housing (inside of the plastic), look here: Leak at rear window -passenger side'ish
[edit]
Part number for the clip is 11546868
Pack of 15 on amazon for $16.70 https://www.amazon.com/au-ve-co-PRO...id=1674343328&sprefix=11546868,aps,651&sr=8-2
If just the gasket, here's one on amazon that I bought and it was a perfect fit: https://www.amazon.com/gp/product/B07H3RTDSW/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&th=1
If you have water inside of the 3rd brake housing (inside of the plastic), look here: Leak at rear window -passenger side'ish
[edit]
Part number for the clip is 11546868
Pack of 15 on amazon for $16.70 https://www.amazon.com/au-ve-co-PRO...id=1674343328&sprefix=11546868,aps,651&sr=8-2
