Nominated for 2014: Best mechanic. Diezel's Auto and Boat repair is one of the most trusted local auto and boat repair shops in Cornelius and Huntersville. When looking for a transmission specialist, Deizel's is the place to go! If you are looking for a trusted location for any of your auto or boat repairs - look no further than Diezels Auto and Mobile Boat repair. They earned the trust of the Cornelius Police Department, and are known for fixing cars and not trying to upsell unnecessary work like all the dealerships do.