You should not have a problem finding a place to do oil changes. The issue you might run into is many mechanics are “afraid” of the Smart because it’s so unique. If you show a mechanic the videos that are available on-line for most service your car will need, I would think most would be willing to tackle the routine maintenance issues. You may find that most of the issues are easy enough you can tackle them yourself. If you are interested in making it easer, there is a free app called Blue Care that pulls many of the videos together and organizes them in the “tutorial” section so you don’t have to hunt for them yourself.
For tires, you may need to order them, but any Walmart will install and maintain the tires with the added bonus that if you run into a problem while out of town, any Walmart will honor the warranty.
For tires, you may need to order them, but any Walmart will install and maintain the tires with the added bonus that if you run into a problem while out of town, any Walmart will honor the warranty.