StormBox Blast 2

Why a speaker in the car? I would be worried about heat killing the battery in it and the speaker long with it and even potentially the car itself if it catches fire. The #1 killer of electronics and batteries is heat, and cars get super toasty. For $400 you could beef up your cars sound system instead if you do it yourself, its not very difficult since its mostly a drop in replacement unless you go out of spec of the factory cables or want to add a subwoofer, unless your car already has a subwoofer thrn its all just getting new speakers and hooking it up. Unless youre going to be taking the speaker out of the car every time you leave your car I wouldnt recommended it, but if you are taking it with you then I've gotten 2 speakers lately that i love. (Balanced, ok decent bass) Soundcore Boom 2 Pro at walmart for $200 or Plus on Amazon for about the same, decent, clear, bass is enough. (This is a light speaker and has a carry strap) (Bass heavy) Tribit Stormbox Blast 2 for $270, very heavy bass especially when plugged into AC(2 prong, you may have one in your car, but it works without being plugged in, i think it loses like 20-30watts?) since it has a dedicated subwoofer. (This one is very heavy, no carry strap) Another speaker i hear highly recommended is the w-king x20 but idk its close to the Tribit though.

If you could push it just a tiny bit, the Soundcore Boom 2 Plus is fantastic at 180, I just got it and I absolutely love it. I had purchased a Tribit Stormbox Blast 2 cuz it was on sale and the Soundcore Boom 2 Pro absolutely stomps all over it and its like 70$ cheaper so I'm returning my Tribit. Its an XL speaker but smaller and lighter than most boomboxes, heavier than most Large speakers. But if youre hard stuck on 150, id say the charge 6, i have the 5 and while i dont use it anymore due to the soundcore i got, i still used it a lot before, the 6 is better in every way and louder than the 5. Just be warned, no real bass in anything under a Large speaker, Charge 6 is considered a Medium speaker. Xtreme4/Boom2 are Large, Boom2+ is XL, Boombox4 is well, boombox size. Also I believe the Charge 6 doesnt have AUX but you can connect and play music thru usb C to it.