"I follow your shop on Facebook, and it looks like you have a very loyal clientele base. It's important to me that I join a reputable shop where I can bring my valued clients over. I have a positive reputation in the industry, and it's important to me to keep it intact."

The interviewer wants to know that you're not just interested in any place that will hire you. They want to know that you want to work for them, specifically.
Before the interview, learn as much as you can about their garage. You can search customer reviews to learn about their reputation. An auto repair shop with good reviews reflects their values as well. Think about the places you have worked. What did you like most about them?
If you can't find much online or through asking around beforehand, try to list at least three things you have read that you like about their garage. Prepare questions for any remaining areas that are unclear, but focus on values and qualities, such as work environment, employee training, and customer care.

"I was immediately impressed by your reputation of being very honest with great customer service. I am hoping to work for a garage that is known for serving customers well. I looked at your reviews on yelp and google and was definitely impressed. I looked around on your website, as well, and I really like how thorough your full inspection is and think it is wise to schedule appointments out to help customers stay consistent with car maintenance."