Since the micro:bit V2 can output 300 mA instead of 90 mA from its 3V pin, you can actually build a motor car with a simple breakout, a L9110S H-bridge motor driver board and a generic, small 5V USB power bank.

This RC car needs another micro:bit (it can be either V1 or V2) as the remote controller.

Required hardware

2 BBC micro:bit V2 (or one V2 and one V1)
a L9110s driver board
a cheap 2WD robot car chassis
a small 5V USB powerbank

Wiring

L9110S	micro:bit V2
B-1A	P1
B-1B	P2
GND	GND
VCC	3V
A-1A	P8
A-1B	P12

And connect your power bank to the micro:bit V2's USB port.

Be noted that many power banks shut themselves off when there are not enough current draw, which would happen when both motors are not running for a few seconds. You can try to turn on the "always on mode" or buy one of those cheap ones that don't shut off.

If you have a micro:bit extension board that offer 5V output (either from USB connection or on-board batteries), a micro:bit V1 can be used on the car as well. Simply connect the VCC pin to the 5V pin.

Upload code

Copy the content of following MicroPython code into the official Python editor, connect the board and flash it:

Controller (to the V2 on the car)
Car (to a V2 or V1)
I also wrote a version for Kitronik's Move:mini with some NeoPixel light effects

In both scripts the RADIO_CHANNEL variable defines the radio channel shared between the controller and the car. Change it if you are going to operate near other people also using micro:bit's radio functions.

Control

Tilt the controller to different directions. Direction arraws would show on both the controller and the car.

The controller can be connected to any USB or battery power.