Cheap/Easy option for Bluetooth Calling & Radio for my '04 ZHP w/ factory HK radio

I recently purchased a '04 330i ZHP that has the Harman Kardon Business radio. I love the car but was disappointed I could only listen to the radio or CD's so I started exploring replacing the head unit with a more modern unit. After looking at the prices I decide that I could use that money for other upgrades instead so tried out this product from Amazon that plugs into the cigarette lighter and plays over an FM station. It was less than $20 so I figured it would be crap, but to my surprise it's amazing! Super clear audio, and the hands free calls work very well. Just thought I would share my recommendation if would rather spend money elsewhere! I'd give it a 8 out of 10 for sound but a 10 out of 10 for price!

IMDEN Bluetooth FM Transmitter for Car, 3.0 Wireless Bluetooth FM Radio Adapter Music Player FM Transmitter/Car Kit with Hands-Free Calling and 2 USB Ports Charger Support USB Drive
https://www.amazon.com/dp/B07F2RTN5Z...p_mob_ap_share

Well, I wouldn't call it cheap per se - I think it is priced right, but you should check out the BlueBus (whole thread on it here). https://www.bluebus.dev/

Not bad, but I have something even cheaper. Buy a cheap aux cable from Ebay, run that to the glovebox. Convert the glovebox flashlight into a 12V receptacle, and plug in a 12V USB charger. Buy a aux to bluetooth adapter, powered by the USB charger. Then plug the aux cord to that adapter.

I think my whole setup cost about $10, to be fair it doesn't have calling, just music/podcasts/videos etc. But it's 100% hidden and more of an OEM integration (says "aux" instead of the radio station) and should the rare occasion occur that someone calls me while I'm driving, speaker phone works well enough.

I picked up one of these off Amazon https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

I was looking for a way to stream satellite radio via my phone (car does not have a sat radio receiver). It has a calling feature and good battery life. I use mine with a short aux cable to avoid accidentally breaking off the stereo jack in the glove box aux port, lest I forget its there and stuff something in the glove box.

With a nice phone mount, it provides a convenient interface to play audio content from your phone over the car's system. You can do video too but no one should be watching videos and driving at the same time. :)

And thanks to t.er for the idea to convert the flash light charger to 12V USB charger.

The flashlight was still in the car when I bought it but I've never used it. I carry a mini mag that's like 100x brighter.