Kevin Lloyd has died of injuries sustained in a heavy crash at Thruxton.
The 43-year-old Wolverhampton-based driver, who only began racing in 2002, crashed on Saturday during a Renault Clio Cup meeting.
He received immediate attention from circuit doctors but succumbed to his injuries in hospital.
Renault UK Motorsport boss Tim Jackson said: "Kevin was a unique character not just in the Renault paddock but in the whole of British motorsport."
Lloyd leaves behind his wife Sandra and two children.