Many advanced features...

Many advanced features such as radar-based cruise control and TV receivers are an increasingly common sight on used luxury models, but according to experts at Glass’s Guide, they are worth only a fraction of their price new.

While the average optional cost of radar cruise control for the Audi A8 and BMW 7-Series is ?1,380, 12 months later its resid­ual value is ?280 – a 79 per cent decrease.

It’s the same for executive vehicles, where a premium audio system is typically worth ?670 on new models such as the Audi A6 and BMW 5-Series. A year later, the set-up adds only an extra ?140 to the car’s price, while a ?700 television receiver plummets in value to ?110 over the same period.

However, not all add-ons are such poor value. Desirable options such as sat-nav and Bluetooth connectivity are in demand on premium models, with some luxury cars and SUVs worth as much as ?2,500 less when the former hasn’t been specified. Meanwhile, sunroofs are making a comeback because so few modern vehicles are fitted with the once-fashionable optional extra.

Richard Crosthwaite is prestige car editor for Glass’s. He said: “After a period when few new cars were purchased with electric sunroofs due to the ubiquity of air-conditioning, they are experiencing a resurgence in popularity.” Crosthwaite reckons they retain more than half of their new cost after 12 months.