A three year term with an apparently unlimited geographic scope would appear grossly excessive, moreso if this is a basic auto mechanic position and the operator doesn't even do business in your new location. However, these issues are evaluated on a case-by-case basis so if you want a definitive opinion you need to consult a local business lawyer with the full facts.
Quote Quoting Nalle Clinic Co. v. Parker, 399 SE 2d 363 (N.C. App. 1991)
A covenant not to compete is valid and enforceable upon a showing that it is: (1) in writing, (2) made part of a contract of employment, (3) based upon reasonable consideration, (4) reasonable both as to time and territory, and (5) not against public policy.