On this page of the Cyberpunk 2077 guide, you will find a walkthrough of the Tune Up side quest. We describe where the headquarters of Delamain HQ is and what attractions are waiting for the V there.
How to start the quest: It will be added automatically after taking part in the incident in the garage from the side quest Human Nature
Delamain will contact V to apologize for the "malfunction" of the cab that led to the accident. You will receive an invitation to visit Delamain HQ for compensation. The building is located in Vista Del Rey in Heywood.
When you get there, talk to the receptionist (AI) on the big screen. You will receive compensation - several thousand credits.
Soon a conversation with the "real" Delamain will start and you will be invited to go to the back room. This is part of the new Delamain side quest: Epistrophy.