[quotethe vehicle preparation costs could be around £500 (servicing, removing dents, etc).[/quote]
And the rest we spend £500 prepping a polo. Main agents will / have to spend a mint preparing used cars, as used car customers generally expect new car condition and mechanical prep can also be colossal esp if it needs a major service and tyres etc. If you put 3k across a used car you may end up with £700 after VAT, factor in advertising costs and overheads and you get a lot less. This is the reason that dealers have such high targets. Low volume = no profits.