I've never had experience with that site as well, but a friend of mine does have a car DVD player from a China manufacturer (Waywell). For the price, I think it works pretty well. But I do have to warn you, the GPS part can get pretty tricky, and if you're not tech-savy then if GPS ever messes up it'll be next to impossible for you to fix. There are certain drawbacks to such a cheap unit, but for the price I honestly think it depends on your budget. You can dish out a couple hundred more for a brand name model that's a year or so old refurb'd.
Hope that helps you decide if you want it or not.
