When I go on a roadtrip, I always try not to bring anything that would defeat the purpose of seeing the sights on the way. I would only bring limited audio, I would usually pack more water and snacks than anything else.
I do not know if I should be saddened by the evolution of lcd to mobility that you can install them in your car. You can have one on each headrest, another one by the rear view mirror or on the dash. You can even set it up to be a full theater system with 5.1 speakers. You now have a home theater in your ride. All you need is a lazy boy. And there goes my ideal roadtrip, right out the window, driven out by the lcds. Sigh.