Seems they are trying to get rid of commercial operations in residential areas.

Using tools not normally found in a residence;

Conducted on vehicles registered to persons, not currently residing on the lot or parcel;

Conducted outside a fully enclosed garage and resulting in any vehicle being inoperable for a period in excess of twenty-four hours.
(See section 5.2.0.B of the Zoning Code)

Other regulations pertaining to emissions are more akin to stopping things like how people used spent oil to keep driveway dust down.
Common sense and no code problems, seems like to me.