The average value rose just by just £1 against July but £503 over last year.
Fleet/lease values increased by 2.3% to the third highest point on record, while average dealer part-exchange values were the fourth highest recorded.
Simon Henstock (pictured), BCA chief operating officer UK remarketing, said: "August was a strong month in the used wholesale markets.
"Prices have improved as inventory has dropped and conversion rates have risen with first time sales – which are critical to churn – also improving.
"Reports from managers across BCA's 23 strong network also bear this out, with both car and LCV sales performing strongly, despite being at the height of the summer holiday season."
He added "Our Pulse report for July saw a steady marketplace with the average values at record levels and August has improved on that performance.
"It has been a strong month with good levels of demand and with the September plate change nearly upon us, we can expect the markets to be very busy indeed over the coming weeks."
Year-on-year table: All cars
| All cars | Avg age | Avg mileage | Avg value |
| August 2015 | 61.15 | 53,926 | £7,839 |
| August 2016 | 57.71 | 51,345 | £8,342 |
