Most motorists say running a car is their biggest financial concern, according to a survey.

As many as 63% of drivers put motoring costs ahead of such worries as paying rent, a mortgage or job security, the poll by Auto Trader found.

A separate survey by the company found that the price of second-hand vehicles fell 5% to £8,620 in the period April to June 2012 compared with the same period last year.

But the price of newer used vehicles has gone up, with those under a year old rising by 3%.

The poll of 2,215 motorists found that 55% had less disposable income in April-June 2012 than in the same period last year.

More than half (53%) were looking for a vehicle that was cheaper to run, with petrol prices being a primary concern for 82% and the cost of car insurance being a worry for 67%.

Fuel-efficiency and saving on insurance were the main factors for 32% of those choosing to buy a new car and for 24% of those opting for a used car.

Among motorists who have bought a car in the past three months, small family cars like the Volkswagen Golf and supermini models such as the Ford Fiesta are most commonly sought after.

Auto Trader group strategy director Tim Peake said: "With the average cost of used vehicles declining, it's easy to make the assumption that now is a good time to buy a used car.

"However, this average drop in price has been caused by an abundance of older vehicles aged 10 years plus in the market, and younger second-hand vehicles are scarce. Therefore, now is also a good time to invest in a new vehicle."