I had the same issue with a vehicle listed as having aircon. However, I realised that it didn't actually have aircon (just an auxiliary heater for the rear) and tried to haggle a bit off.

The dealer told me to take a running jump, as he had two other folk lined up willing to pay over £500 more for the vehicle as he'd not realised it worth more (it was the rare VW T4 Multivan not a regular Caravelle).

However, if you fancy a fight, or if you think the dealer might be sympathetic, act now. Make sure you have copies of the ad that listed the missing features - crucially, was it misdescribed both on the dealer's site and other sites like AutoTrader and eBay? Autotrader handles sites for dealers as well as their own, so they may have relied on automated pre-filled spec listings.

Realistically, the value of these options to a used car's price might not add up to more than a few hundred pounds, so you may have to take it on the chin.

In future, the best way to avoid this is to take the ad and a check sheet and methodically check and tick stuff off. It's all too easy to like the general appearance and price of a car and miss out on the finer details.

The dealer has a duty of care to make an accurate description. The goods are clearly not as described. You have a open and shut case for a claim as long as you have proof by way of an advert or invoice which lists the missing features. If you want money, it would be difficult to put a value on the missing items. You would have to compare this car's price to similar ones with the features, or get the prices for retrofits off a website such as Kufatec - think I would go with the latter as it is more objective.