13. Bumpers and tyres

Paintwork is not the only surface that takes a battering in the winter; bumpers and tyres get a hard time, too.

Treat exposed plastic bumpers and trim with Mer’s Bumper and External Vinyl Gel (£7.99), which repelled water for months in our test.

A tyre shine will also help protect rubber, and keep it looking good.

CarPlan’s Tyre Slik is a frequent test winner.