PCP - sell or terminate 18 months from end

I am 2.5 years into my 4 year PCP on my car and have £14.5k left to pay (£12.5k it if I settle early). I have recently checked the trade in/WBAC/Motorway value which comes back at £10.7k-£11.7k, however on autrotrader the same car is selling between £12k and £14k.

It appears I am either now in negative equity or on the edge of it. Should I consider selling it privately in the hope of taking some money out of it or just let it run into negative equity and voluntarily terminate the contract at some point before the end of the 4 years?