Well, what do you think?
A decent normal headunit costs $200-300 easily. You're looking for a TV screen (motorized), DVD player, cd player combo for $300.
Of course they are shitty. They are cheaply made with crap parts and you're lucky if it lasts 6 months before crapping all over itself.
Do yourself a favor, save up some money, and buy a decent unit.
This right here is why the electronics market is going to shit. Everybody wants something for nothing, thus forcing companies to start making shittier products that they can sell for less money.