Extra 6ft Charging Cables
Most people just use the super short USB charging cable that came with their phone or a cheap $0.99 option they bought at a gas station. Don't do that. Those cables aren't safe, don't offer the faster-charging speeds (because they're cheap) and they're always too short.
Instead, we'll recommend you buy a nice 6ft Lightning, micro, or USB Type-C charging cable from Amazon Basics. These are high-quality yet affordable cables to charge any and all gadgets in your car.
6ft is long enough to reach the back seat, but not so long that you're swimming in cords while trying to drive, or passengers are getting them around their feet. It's the perfect length.