im looking into buying dvd headunit and looking at today's market there is a lot out there. there is a lot of cheap ones and a lot of very expensive you can buy. im not looking at spending a fortune on one. just trying to find the one that gives you the best for your buck. i want one that has "7 screen, preferably has gps sat nav, aux video in or a dtv tuner. what are peoples experiences with them? cheap or decent ones and any recommendations