“Some people have nightmares,” says David Coulthard, when I ask how it feels to watch his son race. “But I have daymares.” That his 15-year-old Dayton is still in karts rather than cars is of little comfort. “It’s knowing I have no control over it, you know? Obviously I have no control over his entire life, but…” After 14 years as a Formula 1 driver, during which time he drove for Williams, McLaren and Red Bull, won 13 F1 races, had two spectacular accidents (in Australia and Malaysia) and count