Hi, does anyone have any genuine experience with the non-oem RNS510 headunits? I have an eBay link at the bottom. Shelling out £450+ for a genuine one is a lot of money, so thought I'd try get some opinions first. Thanks!http://www.ebay.co.uk/itm/261165841648?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649