Comment on Princess Diana Conspiracy Theories by gary.

A sabotage job like that is not that difficult to do really.
All that would be required is to fit an electronic black box to the car that is activated by wireless remote control.
Technically, the wheel speeds to the anti lock brakes and traction control system would go into the black box and then to the brake system, the vehicle would operate normally and nobody would know anything was up until the device is triggered by wireless remote control.
When the black box receives a radio signal indicating ‘now’, the black box would route synthesised wheel speeds to the anti lock brakes and traction control system, two of the wheel speeds would have a slow speed generated from signal generator within the black box, say each wheel would be set to 10mph on the right side of the vehicle. The two wheel speeds on the left side would have normal unmodified speeds, the traction control system would then try to brake and slow down the wheels on the left side to the same speed as the right hand side causing the vehicle to swerve left and hit the pillars.
The black box could de disguised as a taxi meter.
Signed
The mechanic.