We spoke to a Rov about this, not as a shailah, but just to hear more about the inyan. I personally do not listen to music in the car during Sefirah, and am perfectly content with the news and talk show stations. The rov I spoke to said that if listening to music helps to keep a driver calm and therefore able to drive more safely than NOT listening to it, there can be a heter. I would not do it even with the heter, if I had someone else in my car and I knew they don’t listen to music (yeah, I know it’s MY car, I’m doing them a tovah to drive them around, etc. etc., but I wouldn’t want to make someone else uncomfortable).
Bottom line – always ask your own Rov for guidance.