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

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  - 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 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.

Kevin R. Sperling - Service Manager in Watertown WI

Kevin R. Sperling Service Manager

Kevin began his automotive career 20+ years ago through a work/study program while attending high school in Illinois where he was born and raised. He has obtained several ASE Certifications, including Parts Specialist and Service Consultant. Kevin is very knowledgeable and is eager to help our customers fix their cars.

He has also earned a Master Degree in Business Administration & Management and a Bachelor Degree in Cyber/Computer Forensics & Counterterrorism, both with honors.

Kevin is an avid firearms enthusiast who volunteers with multiple law enforcement agencies and enjoys repairing computers, reading, and watching academy award winning movies in his free time.