These terms fall into two categories; the first concerns the design process and the second the vehicle itself
3D CAD surface modeler - The software used to design the form of the vehicle.
Clay - A wax-based modelling clay used to make scale and full-size models of vehicles.
Ellipse guides, sweeps & curves - Drawing aids. Ellipse guides (various sizes and angles) are used for accurate drawing of wheels and other circles in perspective.
Milling - The process by which a clay model is produced from digital data.
Rendering - A top-quality ‘presentation’ illustration, often finished using computer software.
Sketch - A rapidly-produced drawing.
A/B/C/D pillars - These are the parts of the car bodywork that give it structural integrity and provide occupant protection while supporting the roof.
Beltrail - The main structure across the front of the interior, padded for safety.
Binnacle - A port for instruments including the speedometer, fuel and temperature gauges etc.
Cantrail - Interior body structure along the sides of the roof, and above the doors.
Coke-bottle - Word used to describe a car that is ‘slim’ at the centre and ‘bulges’ at either end – like a Coke bottle.
Daylight opening (DLO) - Overall perimeter of the side window aperture.
Derivative - Body style of a given model ie five-door, four-door, or estate.
Homologation - The procedures for certifying that various legal requirements have been met.
One/two/three box - Refers to the overall shape of the vehicle. One box is a van-shaped vehicle, two box is hatchback or estate-type vehicle and three box is a saloon car.
Power train - Engine, clutch, gearbox, axel, driveshafts, wheels.
Ramp angle - Clearance angle from the wheels needed to prevent the risk of grounding the car underside.
Screen angle - Angle of the front windscreen from vertical.
Shut lines - Door opening gaps and similar panel divisions.
Tumblehome - The tilting inwards, towards the top of the side glass and body work.
Wind cord line - The perimeter of the whole door aperture.