Long and Foster Real Estate
Why is this answer important to you? Are you interested in having a car repair business yourself, or are you collecting information to file a complaint on a home operating such a business? I'd be glad to help you further.
Some older properties (possibly on a main road etc) may possibly have been "grandfathered" or are possibly non-conforming and may allow it, but for the most part a car repair business in a residential area is not really possible.
One option you may have: To find a properly zoned commercial property with a residence above it. In many areas, the owner of a commercial property / business may maintain legal residence "above it" in an apartment etc.
Hope that helps.
Brian Luce ABR, SRS,
525 N. Main Street Doylestown, PA