> Does anyone have any recommendations for what to get instead of SOUNDBOKs for my van?

If you want hardware that will last, don't buy stuff that includes remote updatable firmware.

Speakers work fine without firmware. For hardware that does run firmware (like a receiver or controller) get one that doesn't update, and doesn't require updates, unless you find an issue that is solved in an update and which you can opt in to. Most hardware that's on the internet chatting to whoever made it doesn't have a life expectancy past five years or so — it's part of the business model.