Glass's have named the top five optional extras that for retaining residual values.

The key pieces of equipment are; Satnav, upgraded Alloy Wheels, a Panoramic roof, Bluetooth and Air-Conditioning.

Rupert Pontin, director of valuations, said that few options increased the value of a vehicle or made it easier to move on when it resold but that there were some exceptions.

He explained: "Apart from these five, almost nothing that can be added to a vehicle has any real value. Even some options that are very expensive, such as advanced safety features and upgraded audio systems, offer little or nothing.

"Our advice to the new car buyer is that, unless you really want them, don't waste your money by including most options to your new car because you won't get any additional return at resale time."

Rupert said: "Satnav has rapidly become seen as almost essential on any car in the prestige sector and, increasingly, for vehicles below. Having an upgraded satnav with a larger screen and better mapping will also add value for cars in the upper reaches of the market.

"After body colour, wheels tend to have the biggest impact on the appearance of a car. Opting for upgraded, larger alloys tends to improve the forecourt appeal of every vehicle.

"Bluetooth is key for younger buyers, being able to access phone functions and music through the car while on the move is seen as a deal maker or breaker.

"Very few new cars today are sold without air conditioning as standard but, for those that don't, it is always worth upgrading. It is very difficult to sell cars without it. Also, at the upper end of the marker, having climate control rather than bog-standard air con is important."