Launched on 9 July (see MRW story), the public reported 2,400 litter louts on the charitys website with the highest sightings reaching 452 in the South East.
According to the results, Ford drivers are the worst for littering, followed by Vauxhall and Peugeot. Blue cars also top the list as the worst for discarding rubbish.
Keep Britain Tidy chief executive Phil Barton said: So far the campaign has shown how much the public hate car litter and how they are willing to report those who do it. I myself witnessed a white limos passenger chucking a fag-end on the M56 in Cheshire a real turn off.
We hope that by collecting this data we will be able to send out a clear message about the extent of the problem and lead the way in making it socially and legally unacceptable.
Cigarette ends were the highest on the list of most littered items with fast food and confectionary packaging appearing respectively.
The charity wants harsher penalties for littering drivers. It has suggested fining the owner of the littering vehicle and enforcing points on their driving licence, unless details of the culprit are provided.
It is hoped the new findings will help influence policy on motorists who litter.