I have the Archos 20gb AV420, and I have to say I'm super pleased, they make a great little product. The retail package comes with pretty much every attachment you can think of (I'm pretty sure a cig litter charger is in there as well). But the battery holds it charge nicely and even better when you play around with the system settings and such. But look around alittle first, I got mine offa ebay way cheaper then from a store, and I lucked out since it was pretty much brand new and had all the original packaging and such. But I've heard that there are a few new equals coming out from Creative and a few other places. Good luck, keep us posted.
ps- You dont need to hack up your console to have a nice carpc system. hehe just some food for thought.