As a car mechanic and shop owner, I got tired of answering the same diagnostic questions over and over. "Why is my Check Engine light on?" "Why does my car shake at 60 mph?" "Why won't it start in the cold?" So I built an AI-powered diagnostic tool for my auto service website. It's a conversational chatbot that asks follow-up questions, analyzes symptoms, and gives users a preliminary diagnosis — all before they even call the shop. How it works The bot (I named him "Paweł") uses an LLM to: Accept a free-text description of the problem Ask targeted follow-up questions Suggest likely causes ranked by probability Recommend next steps (DIY fix or visit a mechanic) What surprised me Users describe problems much better when talking to a "mechanic" than filling out a form The AI catches patterns humans miss (e.g.…