I sold 3 'nearly new cars' in the past 12 months.
The formula I found that works best is....
list on Autotrader at the Autotrader suggested private price - be prepared this will be thousands less than you see cars listed for but also thousands more than trade bids (WBAC, Motorway).
The Porsche I listed at £84,500 when there was similar cars on AT listed at £90K Plus, but trade bids on mine were around £80k, I listed at £84,500 and it
sold to a dealer within 7 hours for £83,700.
The biggest lesson I learnt is don't be greedy, a few years ago I was selling a Supercar, I got an offer for £150k, but wanted £153k, so turned down the offer, it took a further 6 months to sell....at £129k
If you want to sell privately, make sure you know what a real concrete trade offer is, and expect to get 5% more private sale.
All 3 cars I sold in the last 12 months have gone to dealers, private buyers are either in short supply or quite often expect to pay less than trade.
The other option is collecting cars, where cars seem to sell well, but buyers have to pay a 7% fee, so this will cap what they are ultimately willing to bid.