Tom Benghauser, SatisfactionResearch chief executive, said his survey used random phone sampling. "It will generate findings which are completely representative of the entire UK driving population," he said.
"Individuals or groups cannot stuff the ballot box by volunteering to complete questionnaires on multiple occasions."
The accusation will add weight to the views of carmakers which have expressed doubts about the validity of the JD Power survey since it was launched. Top selling cars, such as Vauxhall Vectra and Ford Mondeo, have consistently performed badly in the survey while niche models, such as the Subaru Impreza, dominate the top spots.
Dave Sargent, JD Power European director, said he was confident there was no "systematic manipulation" of the results. He said the company had security systems in place to make sure there was no abuse. He admitted the Data Protection Act restricted the number of checks that could be made.
"Without access to DVLA records, we have yet to find a better way than through Top Gear of reaching drivers," he said.
Mr Benghauser will post his customer satisfaction data on a website where retail car buyers will also be able to view product information, road tests and part-exchange valuations. The site will help customers select the car most suitable for them, before passing referral details to a subscribing dealer.
Dealers will be charged a "nominal fee" for the initial sales lead and then a "higher but not unreasonable fee" if the sale is completed.
Mr Benghauser said he aimed to create a network of dealers to cover all franchises in each major postcode area. If there was not a local subscribing dealer, customers would be directed to the nearest available source. They would also be offered internet and other sales channels.
SatisfactionResearch.com claims it will contact 300,000 UK households on a purely random basis for its data. The company expects to achieve around 24,000 completed returns. It has already developed customer satisfaction and retention programmes for Pendragon, Arnold Clark, Clive Sutton and Ixion. It has also worked with Saab and Vauxhall dealer programmes.