Eurodyne now offers a reflash for the 2015+ Audi S3. The reflash does not require ecu removal, and with the included powertap flash tool can be by performed by anyone with a windows laptop and an internet connection. Power and torque gains are as follows;

Stage 1 91 octane : 45 hp and 70 FT lbs torque,

Stage 1.5 91 octane: 60 hp and 88 Ft lbs torque,

Stage 1.5 93 octane: 71 hp and 100 Ft lbs torque.

Once you have purchased the reflash, you can switch between available file versions including stock software for no additional charge from Eurodyne. The included flash software will allow you to do datalogging and supports some diagnostic functions such as clearing fault codes. 

*Due to the nature of software products and the inability to verify if your car was returned back to factory software this product is non-returnable.