"Car Talk is the exemplar for consolidation and homogenization on the noncommercial end of the dial," writes Paul Riismandel, adviser to WNUR-FM at Northwestern University, on Radio Survivor. Riismandel notes that "as syndicated programming has taken over the programming schedule of public stations, local news, information and culture is pushed off. Car Talk is a program which pushed the frontier of this movement." He cites the 1997 uproar when Wisconsin Public Radio canceled its popular local About Cars program to carry Car Talk, which culminated in a hearing before the state legislature (Current, March 17, 1997).
UPDATE: For a nuanced view of the About Cars vs. Car Talk controversy, see the transcript for This American Life from April 25, 1997. And thanks for that tip to the helpful blog reader who chooses to remain anonymous.