The service sector, specifically the automotive sector, has witnessed significant growth in the economy and is constantly searching for methods to improve its quality indexes with its customers; however, errors in general repairs are ever present in this tertiary activity. This document undertakes a practical study to measure the effectiveness of the Lean Service Quality (LSQ) model, which combines the development of a multi-elemental scale to measure service quality (SERVQUAL) and a conceptual/practical Lean Service model, with the aim of reducing the number of poorly performed technical repairs at a Toyota automobile dealership. The main result of the research was defining a practical guide to replicate the LSQ model. In addition, as the model’s first approach, the study demonstrated that, for the dealership under study, the rate of bad repairs was ultimately reduced by 5.17%.