I bought back our middle daughters 2008 Ford Edge Limited...long story...given I know the history of maintenance for the most part. We will be driving it for a little bit...I'm going through the car cleaning and fixing some cosmetic things...and possibly letting our youngest daughter drive it within the next year when she gets her license. It has the 6 cd stereo with the Sync function, but the channel selector faces are worn through so I'm wanting to clean that up. I've noticed the sound goes flat sometimes and will come back if I turn it off, then back on....not sure if this is the amplifier, the stereo, or the back speakers. I've found a nice navigation stereo which apparently came out of a 2008 Edge for a decent price...they also have the unit like is in the car currently. I always prefer stock over aftermarket, so that's why I'm leaning towards these units. I've researched and read about installing the nav unit...the part number on the case of the one I'm looking at is AL-1T-18K931-AD...and have read anything from plug and play to loosing steering wheel, sync, amplifier, etc. functions. If they do not have the GPS antenna I know that will have to be sourced at the least, but I don't think they're that expensive. So I'm asking for input in doing this given the thread or two I found here on this forum were from 2007-2013 to see which stereo might be best...