Police in the UK seize 13 supercars after eyewitnesses report that drivers treated the motorway as a racetrack during rush hour on the M11. According to accounts provided to officers, several vehicles accelerated to excessive speeds and then suddenly braked, causing the cars to bunch together. The incidents disrupt traffic during the evening peak period, prompting concern from people at the roadside. The vehicles seized include high-end sports cars such as Lamborghini, Ferrari and Porsche, among others, though the full list beyond those models is not specified in the provided reports. The reports describe police action taken after the accounts were passed to them, indicating a response to reckless driving and traffic disruption. No further details about arrests, charges, or whether specific individuals are identified appear in the material provided. The matter is described as a safety and enforcement action following claims of dangerous driving behavior on a major motorway.