Should I buy an Aston Martin Vanquish as an asset?

I will shortly be retiring and I am anxious to purchase a high quality car that does not depreciate significantly. New model values appear to drop off a cliff. I have in mind the old model Aston Martin...

Government wealth warning

What is the best way to sell a 2,200 mile 2008/08 ASTON MARTIN VANQUISH 5,900 cc S V12 2+2, and what sort of price should I be looking for? The spec reads: Automatic, Oynx Black, Air Conditioning, Airbags,...