

Both are a bit tricky with Usenet. https://abook.link/ covers a good amount of my needs. Anything not found there is usually found at https://forum.mobilism.me/ (DDL) or http://audiobookbay.is/ (torrents).
I’ve had to rely on torrents for older tv shows.
Nothing easy. https://www.myanonamouse.net/inviteapp.php is considered the best private torrent tracker for audiobooks. Getting in requires a little patience.