Your best bet is a private sale, but this can take time.
It is definitely a buyers market and you have to make your vehicle sound more attractive to a prospective buyer than a similar vehicle from a dealer which would come with warranty etc..
It is possible to trade down with a dealer, however as I did this with the wifes car recently.
Traded a '05 Peugeot 206 for a '02 Nissan Micra with a main Nissan dealer and was given cash back.
She only had the 206 for 6 months and just could not take to it.
Overall we lost a few quid but not that much....