You'll have to define "nice" - my ears lost alot to a couple decades of Grateful Dead concerts standing way too close to the tower speakers. RIP Jerry...

I use a Zune in my Toyota Prius all the time, wired into the Auxiliary sound outlet, and it sounds nice to me. And I can also pump it through the home audio system, but usually don't, as wife and kids tend to cringe at a steady diet of Hank Williams, George Strait, Maria Callas, Cowboy Junkies, the Iguanas, and Eddy Yankovic, on constant shuffle. My daughter carries an iPod that she likes but has been unsuccessful with sound quality in her car - the Apple iPod FM transmitter that she got last Christmas has been buggy and full of static, and the Geniuses(TM) at the Apple Store insist it is all in her head, no one else in the known universe has ever had the problem. Great support strategy there, but I digress (still feeling the pain of buying her first laptop with the Apple tax and attitude included...)