Jack White listens to mixes in his car . . . a Tesla with a kick-ass sound system. Most people don't have that luxury. White also records only to eight tracks on two-inch tape, or so I read. Another quirky luxury--or is it some kind of obsession? I never use the car stereo's system to check a mix, because my car system, the stock system in a Chevy Cruze, sounds like crap. The custom system in my old 2006 Dodge Caravan sounded really good, but the best way to check, I think, is how most people world-wide listen--on ear-buds. So, I use a set of Bose earbuds, around $110.00 retail, out of an Ipod Nano, an indestructable little beast. The bass is rolled off a bit, and the mid-highs are up, but they're my go-to way to check how all the civilians out there are going to hear what I'm doing. Still, that can't substitute for the monitors and room I have. Also, listen on 'phones in the studio. Never hurts to check a mix that way.