My musical taste is pretty varied. The Audi radio got ripped out and replaced with a JVC head unit. The speakers and woofer that came with the car are very good. It has DAB so I listen to BBC 6 music a lot - love the indie and sheer mix of session tracks and unknowns. The endless repeats and playlists on R1 started to annoy me.
BBC4 on journeys - afternoon play or the comedy at 6:30. BBC7 is essential on very long journeys a nice mix of drama, crime, thrillers and other plays. BH on Sunday morning is interesting along with the occasional story on scientists and what they discover/get up to.
I have a rock mp3 filled with the Jovi et all from the 80's and this gets played when I'm out for a pleasure drive. Still I like R&B and even house music - 80's child all over again.
"Tocatta et Fuge" - Bach's best ever (my wife calls it funeral music so I can't listen to it in the car

)