Listen to the word of mouth, not the radio advertisements, the experts say. While you might be tempted by a coupon sale, if your neighbor swears by the shop around the corner, give it a chance to give you a competitive estimate.
If you don't think the estimate is fair, get a second opinion. There's nothing saying you're obligated to stick with one shop because they gave you a free estimate.
If you want a larger pool of opinions, try subscription ratings services. Angie's List rates services companies in most U.S. metropolitan regions. Consumers' Checkbook rates service companies in seven metro regions. Each offers evaluations from many users on local auto repair shops, based on price and quality.