
About Our Technicians
World Class Technician status is the highest level of achievement a GM technician can earn. Congratulations John Distefano, a World Class Technician since 2007, and Buick GMC of Mahwah's newest World Class Technician Tomasz Paterek who just achieved his remarkable accomplishment March 23, 2026!
All technicians have the unique opportunity to become World Class Technicians through the training and certifications available from the GM Service Technical College and ASE training programs. The WCT program provides technicians with the opportunity to validate their knowledge and demonstrate their skills to their employers and - most importantly - to customers in all automotive service areas. They are the "one and only GM expert."
Technicians achieve this elite status after satisfying the strict requirements for their respective Mechanical or Body area, which includes obtaining Master Technician Certification in select areas.
Mechanical technicians achieve World Class Technicians status when they successfully complete eight of nine Master Technician Certifications in the Mechanical area, along with the accompanying ASE Certifications. Techs can choose to complete either Engine Performance or Diesel Engine Performance along with seven mechanical-related certifications. These areas are as follows in the chart below:
Course ASE Requirement

Along with John and Tomasz, Buick GMC of Mahwah has a tremendous team of dedicated professionals. Our team members bring a diverse range of training and skills, ensuring exceptional service and expertise for our customers. Each team member is committed to delivering excellence.
Frank Castaldo - With an impressive 30 years in the automotive industry, Frank is a seasoned Automotive Technician who truly knows his craft. His extensive skill set allows him to tackle any vehicle with confidence, making him a reliable resource for both customers and colleagues. Whether it's routine maintenance or complex repairs, Frank's well-rounded experience ensures that every car is in great hands.
William Macdonald - With an impressive 38 years in the automotive industry, Bill is a well-rounded technician whose extensive experience covers a wide array of automotive needs. He has developed a specialty in diesel mechanics, making him a trusted source for those who rely on diesel engines and vehicles. With 38 years of knowledge and a genuine love for cars, Bill is always ready to assist customers with their automotive needs, ensuring they receive the best service and expertise available.

Justin Frank - Future World Class Technician - 11 Years of Excellence in the Automotive Industry. Justin is a highly skilled and dedicated automotive technician with over a decade of experience driven by a genuine passion for cars and motorcycles. Throughout his 11-year career, Justin has demonstrated exceptional technical expertise, earning the coveted ASE Master Technician certification across eight critical categories. His extensive knowledge spans a broad spectrum of automotive repairs, including high-performance engine work (both gas and diesel), HVAC systems, EV, and routine maintenance, making him a versatile and reliable professional in the industry.
Justin is committed to continuous growth and excellence, actively working towards attaining the prestigious World-Class Technician status. His relentless pursuit of mastery, combined with his hands-on experience and technical proficiency, positions him as a leader in the automotive field and a trusted expert for complex repairs and performance enhancements.
With a passion for innovation and precision, Justin Frank is dedicated to delivering exceptional service and advancing his skills to meet the highest standards of the automotive industry.
Matthew Crosby - Future World Class Technician - Matt is our "Rising Auto Technician" with three years in the automotive industry, Matt has quickly established himself as a dedicated technician. His journey began as a lot attendant, but his eagerness to learn and grow led him to train as a technician, where he has honed his skills with impressive speed and thoroughness. Matt specializes in electrical issues and has a keen focus on the latest in electric vehicles (EVs). His passion for all things automotive sparked during high school when he took an auto shop class, igniting a lifelong interest in cars and technology. With his growing expertise and enthusiasm for the automotive world, Matt is committed to providing exceptional service and innovative solutions to meet the needs of every customer. Whether it's troubleshooting an electrical problem or working on cutting-edge EVs, Matt is ready to tackle any challenge that comes his way.
Jose Ilagan - With a decade of experience in the automotive industry, Jose has a diverse skill set that covers everything from Pre-Delivery Inspections to thorough assessments of pre-owned vehicles. His expertise also extends to diagnosing a wide range of customer cars, ensuring that he can tackle any issue that comes his way. Jose's hands-on approach and passion make him a mechanic by trade and a gearhead by choice. He thrives on getting his hands dirty and enjoys the challenge of solving problems under the hood. His commitment to excellence means that every vehicle he works on receives meticulous attention and care. With Jose's blend of knowledge, experience, and enthusiasm, you can trust that your automotive needs are in capable hands. Whether it's a detailed inspection or a complex diagnosis, he's dedicated to delivering top-notch service and keeping your vehicle running smoothly.
Elias Martinez - A recent graduate of Rockland Boces with a major in Automotive Technology. Elias's goal is to become a GM world-class technician. In his free time, Elias loves working on his cars, attending local car shows, and spending quality time with his family. His passion for cars and dedication to his craft drive his pursuit of excellence in automotive repair.