About Northside Auto
in Watertown, WI

Meet The Team at Northside Auto, full service preventive maintenance and auto repair center in Watertown WINorthside Auto is a full-service preventive maintenance and auto repairs center in Watertown, WI, specializing in a range of auto repairs and services for cars, trucks, vans and fleets which include: heating and cooling, transmissions, electronics, internal engine, heavy-duty, towing, undercar and more.

Our experts have the knowledge and skills to service and repair even the most challenging auto problems on all makes and models of domestic and import vehicles. We use the latest technology to assess the situation and offer you alternatives. We guarantee all of our work and know you'll be happy with the outcome. Stop in or give us a call at (920) 206-9434 to let us know how we can help you today!

Meet Our Staff at Northside Auto

John Mason - Owner at Northside Auto, full service preventive maintenance and auto repair center in Watertown WI

John MasonOwner/Certified Master Technician / Mechanic

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

John has been married to his wife, Jolene, for a number of years and they have three boys together. In their spare time, they enjoy camping, fishing, and snowmobiling together as a family.
Mary Jo Olson  - Assistant Service Advisor & Office Manager at Northside Auto, full service preventive maintenance and auto repair center in Watertown WI

Mary Jo Olson Assistant 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 - Master Technician at Northside Auto, full service preventive maintenance and auto repair center in Watertown WI

Greg A. NassMaster Technician

Greg A. Nass will be taking on service technician duties at Northside Auto Service on Hwy. L, just one mile north of Watertown. Greg brings over 19 years of automotive repair experience to Northside Auto. He graduated from Madison Area Technical College in December of 1995, and has had much updated training along the way.

He is currently an ASE (Automotive Service Excellence) Certified Master Technician. Greg began his new position on Monday, August 26, 2013. John Mason, owner of Northside Auto said “Greg is known for being extremely Dependable, Knowledgeable and Honest. We at Northside Auto are very excited about him coming on board. He will be an asset to our operation and help us to deliver the highest quality customer service possible, as we expand our business.”