This might happen almost entirely in secret, or as a way of promoting the brand at an international motor show, or something in between. Concepts of one kind or another have been around since at least the 1930s. Many remain in the public memory for years, but most are quickly forgotten as soon as a new batch turns up. For example, do you remember this remarkable concept limousine from Citroën in 2010?

From many hundreds of possibilities, here are 44 of the perhaps less well-remembered concepts in automotive history, listed in chronological order. If you recognise more than ten of them, you’re doing very well.