If you already have a J3 Chip and Programmer and just want a Midnight Tune, you can purchase one here.

The stage system remains the same as purchasing a full chip, read about the different stages below:
 
Stage One: A general enhancement to the tune, Fuel mixture is enleaned at WOT to promote power and Economy and Timing lightly changed to improve flatspots and engine response. The on-board SmartShield Security can be optionally disabled, otherwise after the chip is installed, you will need a scan tool to reset the security system to match.
 
Stage Two: Everything in Stage One with further enhanced fueling, modified factory O2 sensor settings, and the full Midnight Spark remapping for maximum power and efficency gain. Transmission settings have also beein lightly tweaked to improve automatic shifting (If the car is Auto). This Stage provides a substantial improvement to the feel and performance of the car.
 
Stage Three: Everything in Stage Two, with an uplifted fast cut limiter, tweaked knock settings and further optimised Automatic Transmission settings. This stage provides the ultimate enhancement to your AU.

Make sure to fill out all the options below to suit your AU. You can also request any further customisations to the tune using the "Additional Tune Requests" Field.