1. Toys and games
Today's children generally don't have much interest in I-Spy. For younger kids, a favourite teddy or two to cuddle should do the trick. For the older generation, buy them a phone game or two as a present.
2. Sweets and treats
Not the healthiest foods, but on a long journey, the trade-off is well worth it if you want your kids smiling rather than screaming. And you do. Stick to non-messy sweets, so steer clear of bags of sherbet!
Simple but important: dehydration is no fun for anyone. Plastic bottles with resealable caps are the best option. Bear in mind, though, that too much water may lead to a hasty toilet stop a little way down the road!
4. DVD player
Newer cars may already have these fitted, but in the used cars, most families drive you'll need to pick up a portable model. They're cheap and robust, so don't fear for their safety. Just make sure you provide some favourite movies or cartoons, too.
5. First aid kit
Kids are always finding new and inventive ways to hurt themselves, so be ready for the inevitable scrapes. You don't want to find you're out of plasters while your child is smearing a bleeding finger across their sibling's face!
Used and new cars alike boast storage spaces, door bins, etc. Fill these with music in whatever formats your car can use. Steel yourself: yes, you will have to listen to your child's favourite TV themes for the 200th time. It's worth it. Really.
7. Warm blankets
Kids aren't as good at regulating their body temperature as grown-ups, and they also get tired pretty fast. That means they can become cold quickly, so having a simple blanket or two to cover them while they rest is a really good idea.
8. Batteries and chargers
However far you're travelling, batteries never last long enough. You don't want to find this out during a 200-mile slog down the motorway, so always carry a charged power bank. AA batteries may also be useful for portable games.
Letting your kids take photos is a fun way of staving off boredom. If they don't have their own phones, buy a couple of cheap cameras – disposable ones aren't recommended, as they won't be able to see what they've snapped.
It may sound old-fashioned, but many children can have their mind taken off a long journey with a book. Surprise them with a new title you know they really want and "Are we nearly there yet?" can quickly change to "One more chapter!"