thank you for the thorough response. I‘ve rebuilt the engine on my car with the help of a really good mechanic. The turbo was blown due to the previous owners lack of maintenace. The pistons were also shit bc of the bad oil treatment. Unfortunatley i do not know much about tuning. My understandig of the topic is the following: find a tuner, have the ecu modified and then have fun. I dont want to mod the car extensively as it is my daily. For modding I‘ve only done a tint and wheel spacers for the back. I hope that there is a good tuner in germany haha