70k miles on my ride, no warranty issues (knocks on wood) so an extended warranty would have been a waste of money for me. $24k would be easy to get for this as i went to trade in my car and got that with no issues with 65k miles on it. didn't do it though because i'm about $3k upside down and didn't want to add that to an already expensive rubicon.
sell it outright and you'll get more but $24000 isn't too out of the question. dealer won't give you crap for any aftermarket items. more than likely they will say it depreciates the vehicle's worth.