For decades, Ron Arth’s days began and ended at George V. Arth & Son, his family’s 145-year-old auto repair shop on 10th Street in downtown Oakland. As owner, Arth worked alongside a faithful crew and his trusty assistant of 43 years, Renee Camp.  “I have customers who come in and say, ‘I used to come in with my grandpa,’ and I’d say, ‘yeah unfortunately I remember your grandpa,’” Arth joked in a recent interview.  But the end of an era—a long era—has come for the family-owned auto shop. On Nov. 29, the national auto repair company Crash Champions announced their acquisition of Oakland’s oldest—and perhaps the nation’s oldest—mechanic’s garage. Heidi…