The answer is camouflage, which presents its own dilemma by ironically attracting attention to their still-secret prototype. This means camo has to be very effective at confusing the eye and, while it often looks the random application of car bras and bad ’70s wallpaper, there is actually quite a science to it.
With spy shots coming in thick and fast, it’s worth revisiting this video showing how BMW engineers designed plastic masking panels to a BMW 5 Series Gran Turismo on computer and then fit them on to the real panels to disguise everything from the shape of doors and headlights to the car’s entire silhouette.
Rubber mouldings are also neatly fitted inside the car to mask the dashboard, door cards and centre console while still ensuring everything is functional.
They even go as far as applying stickers with pictures of door handles, fuel cap and wing mirror repeater lights over the real things to hide their true shape.
As you can see from the above picture, the end result in the video is a very different looking car.