If your current radio has an aux in you can get a very cheap Bluetooth module to add to it. Connect to switched 12v and aux in and you are done for about £20.
Well, it sort of does because we had it hacked to add an aux input that overrides the FM feed when you connect to it...but now FM mode has got a fault and will only come out of one speaker, which put the kibosh on both the Bluetooth FM transmitter and the aux in :(
If your current radio has an aux in you can get a very cheap Bluetooth module to add to it. Connect to switched 12v and aux in and you are done for about £20.
Edit: eg https://www.ebay.co.uk/itm/384165843565 although that one doesn't have a microphone which some do