The increasingly complex variety of cars for sale on forecourts is confusing customers.

And as a result some 'niche' vehicles are experiencing limited demand on the used market and values are suffering as a result, according to EurotaxGlass’s.

It says that in the past 25 years, manufacturers have massively expanded their product offerings for example the MPV, SUV, MAV and the recreational 4x4 with certain products attempting to incorporate key elements of all these segments.

"The key question is whether this bewildering array of used cars will be able to establish a presence and a following on the used car market," says Adrian Rushmore, managing editor at EurotaxGlass's.

"A number of factors hold the key to success not least of which is price, but with niche products particularly, it is the vehicle's ability to provide a unique selling proposition that remains crucial. It is in this respect that some models have been found wanting and used values have suffered as a result."

Classic examples of this phenomenon are the Renault Vel Satis and Avantime which confused buyers and limited demand.

“Today's market is littered with examples of cars that could be considered ill-conceived, or at best the result of poor market research,” said Rushmore.

“The Vauxhall Signum, Ford Fusion and the VW Golf Plus are all examples of models that sit uncomfortably within the used car market and retain disappointing residual values as a result. The Golf Plus is worth less than a standard Golf despite costing £600 more when new. Clearly, in some instances buyers are not willing to compromise on the style of the standard car for the practical advantages of additional space."

Manufacturers will always seek to provide customers with a broad choice of products, but above all, he said, those products need to satisfy the real needs of consumers if they are to survive in a crowded used car market.

“It is perhaps not surprising that with the ever increasing diversity and number of new models on offer, the trade find it difficult to keep their product knowledge up to date. The danger is that the key selling features used to sell a new car may not be communicated as effectively when that car is offered by the used car market in a few years time. This inevitably impacts negatively on residual values. This effect could be negated if franchised dealers retailed more three year old cars of their own marque. However, the prospect of this happening is as remote as ever.”