I've just sold the MINI, and bought a new (2nd hand) car....
I advertised the MINI on pistonheads after I found the car I was after... It's a great time of year to buy any car at the moment, the market slows over christmas and new year!
I was just fortunate that I managed to sell the MINI as well

Mind you, I had no calls for two weeks, then three came along at once.
If you're after something thats in good supply (i.e. always a good one up for sale somewhere) then stick the MINI up for sale, and wait till someone takes the bait before buying. If you don't need the cash for your next purchase, buy your new car now, and advertise the MINI in the spring, when you can sell it easier and stick the price up by £500.