Not sure how good the GPS is, but wireless backup camera and lifetime map support, 7" screen all for just one low payment of $78 with free shipping :
http://www.ebay.com/itm/7-4GB-Car-GPS-Navigation-Wireless-Rear-view-Camera-Bluetooth-AV-IN-Free-Map-XA/221987555821?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D35696%26meid%3D7c3aad4b1639417ab2d1a4bcf1bd8553%26pid%3D100005%26rk%3D3%26rkt%3D6%26sd%3D381358951881#rwid