Analysis of claims data from 5,332 bodyshop repairs, costing £4.9 million, has exposed the smokescreen faced by fleet managers trying to get to grips with accident statistics.
The research reveals that drivers provide vague or misleading information about how their cars came to be damaged.
For example, more than half of all company car drivers involved in collisions blame the third party for the crash, but half of those cannot name the at-fault driver, instead claiming their cars were 'hit while parked'.
Among the company car drivers who 'owned up', the two biggest causes of accidents were reversing (11%) and hitting the car in front (10%).
Insurance broker Willis carried out the research using its DRIVE Accident Management service, and its sales and marketing director for motor initiatives Graham Harris said: 'What this data does highlight is the importance of assessing where your costs are being incurred before taking action.
'Fleet operators investing in driver training should ensure that the training pays specific attention to reversing or manoeuvering - most training concentrates on forward movement.
'Access to this type of data is critical in understanding and managing risk exposures.'