Dark sports car on the open road

Wisconsin Mechanics Delivering Exceptional Auto Repairs

Here at Northside Auto, quality never takes a back seat. Our auto repair services are steeped in precision and excellence so that our clients receive nothing less than the best. Since opening our doors, our mechanics have honored a diligent work ethic. It’s for this reason why we’ve remained a highly sought-after source for auto repairs. Between our cutting-edge technology and knowledgeable professionals, we’re equipped to fulfill a variety of needs. From various makes to different models, we work on both domestic and import vehicles alike. When you place your trust in our mechanics, you gain access to wide-ranging auto repair services that promise satisfaction.

John Mason: Mechanic Turned Business Owner

From a young age, John had a passion for the auto industry. In high school, he worked at a gas station where he received training to become a mechanic. Eager to gain more knowledge, John studied auto repair and technology during his college career. Following his graduation, he worked at numerous auto repair shops. With his experience as a mechanic and industry insight, John felt confident in his ability to start his own business. In 2000, he did just that. For two decades, Northside Auto has been a reliable auto shop for those in need, and John hopes his enterprise will continue to grow by leaps and bounds.

Northside Auto team

Meet Our Team

  • John Mason
    John MasonOwner / Certified Master Technician

    John grew up in Beaver Dam, Wisconsin, and has been around the automotive industry almost all of his life. In high school, he worked at the local gas station, gaining knowledge and hands-on training at an early age. He then attended UTI in Chicago after high school, studying all areas of automotive repair and technology.

    Before opening his own business, John worked for a number of auto shops throughout the Watertown area including a Chevy dealership as an auto technician. After a few years, John felt he could take everything he had learned both in shop and in school and open up an auto shop of his own.

    In 2000, he officially opened the doors to Northside Auto in Watertown, WI, working by himself at first and hiring employees along the way. Over the years, Northside Auto expanded to a full auto repair facility and has doubled in size.

    John has three boys, and in their spare time, they enjoy camping, fishing, and snowmobiling together.


  • Mary Jo Olson
    Mary Jo OlsonAssistant Service Advisor & Office Manager

    Mary Jo was born and raised in Watertown and studied Administrative and Business Software Applications at Madison Area Technical College where she graduated with high honors. She has over 10 years of customer service experience, with 8 years in real estate. Mary Jo also obtained service writer training at Management Success! Service Writer School in Glendale, CA.

    In addition to service writing and managing the office, Mary Jo's duties also include marketing, follow ups with customers, and providing shuttle service to and from the shop.

    Mary Jo has been with her husband, Brian, for over 20 years. They reside in Watertown and have one son and three dogs together. In her free time, she enjoys spending time at the Jefferson County Dog Park, fishing and boating on Lake Michigan, and cheering on the Green Bay Packers.


  • Greg A. Nass
    Greg A. NassMaster Technician

    Greg brings 30 years of automotive repair experience to Northside Auto. He graduated from Madison Area Technical College in December of 1995, and has completed many additional training programs along the way.

    He is an ASE (Automotive Service Excellence) Certified Master Technician and joined our team in August of 2013. John Mason, owner of Northside Auto said, "Greg is known for being extremely dependable, knowledgeable and honest. We are fortunate to have him on board. He is an asset to our operation and helps us to deliver the highest quality customer service possible."

    Greg and his lovely wife, Anna, have four children and three grandchildren. When he's not busy fixing cars, he enjoys hunting, fishing, camping, and spending time with his growing family.

  • Joshua Martin
    Joshua MartinAuto Technician

    Josh has been working in the automotive field for several years and is currently earning his Degree in Automotive Technology through Waukesha County Technical College. He has a positive attitude, works hard and is a valuable addition to our team at Northside Auto.

    Josh is very passionate about cars and loves working on them. He also enjoys playing his guitars, fishing, hiking, traveling, and spending time with his girlfriend.


  • Matt Olson
    Matt OlsonAuto Technician

    Matt's interest in mechanics began at a young age repairing and maintaining antique farm equipment with his Dad and Grandfather. He continued to gain valuable experience in school where he discovered his passion for the trades while designing and building sets for theatrical productions.

    Matt has been employed in the automotive field for a number of years since then and obtained his Hunter Alignment Certification while working for large tire corporations in the area.

    In his free time, Matt enjoys 4-wheeling with friends, hunting & fishing, camping, attending antique tractor shows, and hopes to meet the future Mrs. Olson soon.


  • Josh KuhlAuto Technician

    We have welcomed Josh to the team at Northside Auto! He began his automotive career working for Dairyland Auto Center in Randolph, WI many years ago while still in high school and later earned his Automotive Technician diploma through MATC. His experience, knowledge, and lifelong passion for motorcycles and hot rods makes him a great addition to our team.

    Josh resides in Beaver Dam, and when he's not at the shop, he can be found hanging out with family and friends, riding his motorcycle, or shooting pool for the Fox Lake Pool League.

    He is proud to be a hardcore Brewers, Badgers & Packers fan and member of Eagle Riders of Southern Wisconsin. Josh also enjoys touring whiskey distilleries and looks forward to attending concerts again.