The auction firm has been tasked with managing the disposal of part-exchange and unwanted over-age stock.
In the first sale, at Manheim Auctions Wimbledon, conversion rates averaged 85% and prices achieved 102% of reserve. More than 200 vehicles a month are being entered in the sales, ranging from a Mercedes-Benz SLK Kompressor to a Volkswagen Polo 1.4 S.
To enhance residual values vehicles are refurbished, while some have a 40-point inspection backed by a five-day money-back guarantee.
Fergus McNeill, trade buyer/auction co-ordinator for Mercedes-Benz, said: 'Since the launch of this programme, our residual values have risen consistently, thanks to the expert advice and high standard of vehicle preparation by Manheim.'
A selection of some of the best prices achieved to date include a 99T BMW 318 convertible, with 40,902 miles, that achieved £12,650 (107% of CAP), a 01 Y-reg Jeep Cherokee 4.0LTD, with 27,944 miles, that made £17,200 (113%) and a 01/51 MINI Cooper, with 8,395 miles, sold for £11,600 (113%).