Tesla has sent emails to owners telling them that if they want to refer family and friends for unlimited supercharging, they need to do it by September 16th, 2018. After September 16th, they will only receive 100$ worth of supercharging credit. The referral is available for Model S, Model X, and Model 3 Performance (P3D). If you need a referral you can click on it below or give the name followed by the four numbers to your sales person (ahmed4472): http://ts.la/ahmed4472