LOL at needing a headlight maybe on a £100 shitter perhaps.
A Cat D is a total loss write off, it is uneconomical to repair, the parts and labour outweigh the value of the car.
Definitions here:
A Category B Vehicle is a Salvaged Vehicle, which is so structurally damaged, or devoid of parts that it is not possible to repair it economically or safely. A Dealer who purchases a Category B Vehicle (a "Category B Dealer") shall be allowed to remove salvageable parts, and shall then be required to dismantle the Category B Vehicle and crush the shell, frame and chassis in accordance with ABI guidelines. Air bags and seat components must be properly disposed of in accordance with manufacturers instructions, the insurance industry requires that these items must never be resold.
The processing of Category B Salvage must comply with the guidelines displayed in the "Code of Practice for the Disposal of Motor Vehicle Salvage" (ABI Code of Practice) issued by Motor Conference. (See 10.2.1 of this Document)
A Category C Vehicle is a Salvaged Vehicle, which is damaged to the extent that the retail cost of repair to the vehicle exceeds the retail pre-accident value thereof.
A Category D Vehicle is a Salvaged Vehicle, which is damaged to the extent that the retail cost of repair to the vehicle does not exceed the retail pre-accident value thereof.
A Category X Vehicle is a vehicle which has been subject to an insurance claim but which has sustained minimal or nil damage or which may have been repaired in accordance to manufacturers specifications, and therefore categorisation as per the Code of Practice for the Disposal of Motor Vehicle Salvage does not apply.