5 things you should never say to a mechanic, DIY with Scotty Kilmer. What not to say to a mechanic if you want your car repaired correctly. How to talk to a mechanic. 5 tips for automotive maintenance and repair. How to fix a car correctly and not make mistakes. Mechanic tips and tricks for the best car repair experience. DIY car repair with Scotty Kilmer, an auto mechanic for the last 50 years.