Not looking to change the radio of the car (Mercedes W126) , but is there an adapter where I can use bluetooth to stream tunes to the speakers ?

Built in adapter would be preferable. Since this car obviously doesn't have headphone or AUX jack would be interested to know the options I have.

You can try something like this

No relation to me, it was the first listing when I searched for "FM Transmitter". You tune your radio to the same frequency, and the music plays back from your own private FM station built into the unit.

thanks, used one of these before but seems the power to cigarette lighter doesn't have a constant flow. mechanic suggested changing to a larger fuse, but for an old car not willing to take the risk.

currently just using a portable bluetooth speaker, but definitely want something more permanent (and connected to the car's power)

So why not get one of those after market cigarette lighters, and connect that to the battery of your car? That way you know exactly what wire goes where, and you do not touch the car's existing wiring. You can now plug in the FM transmitter, and as a bonus most after market sockets have USB power also.

https://shopee.com.my/Car-Tape-MP3-MP4-Mobi...nMaAmWwEALw_wcB

just to check, for the Bluetooth adapter that plugs into cigarette lighter, does it need to be removed when the car is off to prevent battery drain ?

or should be alright if the car is being run every 3 or 4 days.