I've got more experience of buying and selling cars than I care to recall. Parkers and What Car's guides aren't worth the paper they're printed on.
CAP and Glass's is what the dealer will use and even then, only as a rough
guide. Just because autotrader cars are all listed at £10k+ doesn't mean thats what they're selling for. The LC and LCR are notoriously difficult cars to sell due to their high insurance groups. The majority of people who would like to buy one are often put off by their insurance quotes on such a car.
According to Glass's
guide, a car like Snoopie's, 03 LCR 210 @ 20k miles is worth £9130 as a
trade in. IMO £10k is pushing it for a private sale. It'll sell relatively quickly for £9500 as dealers will be selling similar cars for around £10800 and traders for £10k.
For Simon:
As the car is in "average" condition, you're looking at a trade in price of £7880. Possibly £8.5k in a private sale but no more IMO.
I think its very important not to overdo your advertisement price. Whereas it can be argued that you're building a buffer for yourself by adding £500, it can also be argued that if you price the car at your "acceptance price", you'll get the lion's share of interest from buyers as they'll always go for the cheapest option between two or more otherwise identical cars. Always remember though that if you do business in this way, you need to set your price and stick to it. Tell buyers that you're not going to be moved on price when the haggling starts. If you've priced your car correctly, they'll buy it at your advertised price rather than organise more viewing trips to "more expensive" cars with the possibility of not being able to haggle a better deal.
And the most important one of all, if you're free of finance, NEVER ever trade the car in at a dealer, you will almost always lose money this way. It may be convenient but its also expensive.