Figures from the CAP Black Book editorial for September show that retail demand has remained static and, as leasing companies continue to extend contracts, the number of 2000-registered cars continues to be low.
CAP said: 'Some of our research suggests this could knock on to the X-plates which are due to be de-fleeted in the coming weeks. If so, there will be even more of a void in the short-term market.
'Although there are just as many nearly new ex-rental and manufacturers' sales as ever, numbers on offer are often down on the norm.'
In its weekly disposal market overview, Manheim Auctions also noted a buoyant market, driven by a lack of quality stock.
Manheim said that quality vehicles are achieving high prices. A spokesman added: 'As the previous months of this year have shown, anything at present with low-ish mileage, good condition, good colour and full history are achieving whatever the market dictates. It appears that the more spec a vehicle has then the easier it is to retail.'
High mileage fleet vehicles are failing to generate interest among buyers, according to CAP. 'The only negative aspect of the current market is the trade's reluctance to go for cars with more than 100,000 miles, even in clean condition.
'There is evidence that this is partly driven by some finance houses' unwillingness to expose themselves above certain mileages,' it said.