As the following chart from Barclays shows, both new- and used-car sales have collapsed...

While the slump in consumer confidence remains a major factor...

But as Edwards notes, a number of other factors are colliding simultaneously to hurt UK car sales:

The rise of apps like Uber, Gett, and Lyft are making car ownership in urban areas less necessary.

British people have a close to zero household savings rate, and way too much debt, making further car purchases difficult.

Consumers are afraid a recession might be coming and have reduced their spending on expensive items.

The PCP car loan trend may have peaked, flooding the market with nearly new used cars.

A number of car manufacturers are offering "diesel scrappage schemes" in which they take your old diesel car if you trade in for a newer, cleaner vehicle.

The government announced it would ban sales of all petrol and diesel cars by 2040.