I don’t (or at least try not to) swear around my ma. She doesn’t like hearing them and that’s enough reason for me. Of course every once in awhile I may drop one purposefully, for the little kick of annoying my ma. I share some of her sentiment though. In general I think swearing can be a bit vulgar/unpleasant, so I don’t necessarily try to swear at every opportunity, but I do when I’m not around her.
Any old smartphone with an audio jackand/or bluetooth capability will work TBH. Assuming you will just use spotify, the internal storage would usually be enough to save playlists offline for roadtrips without wifi. You can find MP3 players which are essentially stripped down smartphones to be exactly that if you really want something new though. Here’s one on amazom https://a.co/d/8DIz1Qq.