The site, gm.ebay.com, will allow car buyers to haggle with dealers. As with eBay's traditional format, shoppers can agree to pay the advertised ‘Buy it now' price or can use the ‘Best offer' option to negotiate a price.
The scheme will be trialled until 8 September in California, with 225 local Chevrolet, Buick, GMC and Pontiac dealerships participating.
‘As the dealer showroom expands from the parking lot to the laptop, this makes it easier for a customer to browse available new-car inventory, make an offer, buy it now, or send a message asking for more information from a dealer,' said Mark LaNeve, GM vice president for US sales.
Last month, GM rolled out a new website where GM customers can share ideas and concerns directly with chief executive Fritz Henderson.
GM is in the process of selling it European business, including the Opel and Vauxhall marques. Bids have been made by Canadian components manufacturer Magna and Belgian private equity firm RHJ.