The team at Gemini have made it really easy to connect your MotorCheck account. Here are the steps
Within Evolution go to Utils > System Configuration > Default Nominals & System Settings
Then click on Defaults > MotorCheck where you enter the client ID and Secret that MotorCheck will provide you for Gemini.
And that's it! You will now see the MotorCheck button in Gemini's Vehicle Stock Book and Part Exchanges in Evolution and the Showroom System.