Use hook-up wire to carry GND and VIN to the front of the tiny breadboard.

Break-off three extra long headers... and trim one leg short.

Boosting two AAA batteries into 5V requires a step-up regulator... the Texas Instruments TPS6120x can provide ~600mA - which should be just enough to get the job done.

Solder the headers to the regulator leaving the shutdown pin empty.

Solder the battery leads to the headers on the under-side of the regulator.  

Insert the regulator...

• Regulator VOUT - Metro VIN
• Regulator GND - Metro GND

If you're worried about shorting add some shrink tube.

Add a bit of double sided tape to the battery case and slap it on the back of the chassis.

Extra-long headers can be used to turn sockets into pins... remove the servo leads from the connector.

Insert an extra-long header pin into the socket.

And add some shrink tubing - and repeat the process for each of the three servos.

For the distance sensor, you'll have to solder the leads to the extra-long headers.

Connect the servo and distance sensor to the Metro as follows:

• A0 - Distance Sensor
• D5 - Steering
• D6 - Left Servo
• D7 - Right Servo

Ready for some software?