I think that most forms of classical music are best apreciated in front of a quality home stereo setup on a quite weekend afternoon while reading a good book. I enjoy classical music as much as the next guy, but while it works great and musical nuances are easy to hear in your living room or den, a moving vehicle is not going to be the right place for that kind of musical reproduction, unless you purchase a $75k vehicle. Then I would expect that kind of musical excellence, but out of the Prius...?
Most forms of classical music do not lend them selves to mild mannered, but not highly noise insulated mid priced vehicles. The issue is that the very high ranges and very diminuitive sounds that classical music tends to produce, especially during the most stirring and emotional pieces, aren't typically meant to be heard while barreling down the highway at 70. The wind noise and other road noises basically create a cover that causes slight sounds to be washed out.
Ford radios used to have a compression function which would essentially monitor CD ouptut and try to enhance soft sounds or light sounds and would take extraordinarily loud or stron sounds and bring them down a little in order to make music more "hearable" while driving. It has also been my expreience that Ford's speed sensitive volume system is the most flexible and adjustable of any of the speed sensitive volume systems I've encountered. I would say that classical music "survives" a little better coming from a Ford radio, but not much better.
I was a bit surprised that the Prius didn't have a more sophisticated radio, such as having speed sensitive volume, when I purchased it, but it did not prevent me from purchasing an otherwise fine vehicle.