This is most likely one of the most common questions found throughout the world of automotive ownership. Unfortunately in my personal experience, there isn't any easy or straight forward answer. With this article, I will hopefully be able to provide some insight and information regarding this subject based on my own personal experiences or what I have observed in the past. There is various methods which can be used, all to which I will provide an in depth explanation about. Even having an automotive repair background, it still does make it somewhat hard to form an opinion just by walking in the front door. There are various types of characteristics which one would think qualify a repair shop for their quality of workmanship, how well they are able to troubleshoot a fault, and business honestly or acceptable business etiquette. Some of these characteristics can include the age of the mechanics working at the facility, how many years have they obtained their licenses, how many years of operation has the repair shop been in business for, what type of repair shop are they (privately owned or dealership), presentation of their facility, do they specialize in a specific automotive manufacturer, or business ratings such as Better Business Bureau. Regardless of what that information is shown to be upfront, this still does not guarantee a solid answer. For example, I have heard of mechanics who worked in the profession for 20+ years at a new car dealership claiming warranties on customer's vehicles just so they had parts to fix their ownv vehicle. In another scenario having seen a customer's car taken into a dealership's auto body repair shop, to be someone's practice slate and being completely destroyed. On the other end, I have seen small privately ran repair shops in the most questionable of areas produce top notch service with high quality workmanship and very reasonable rates.
Now beyond any of that upfront presentation I mentioned previously, word of mouth is probably one of the stronger ways to form an opinion. This might be something said by a family member, friend, co-worker, or a stranger on the street. This is information based on what someone's experiences were in the past on their own vehicle. Even when you stop by that repair shop and just happen to have that chance to ask in private a customer who is currently having their car serviced, take that opportunity. It never hurts to try, and remember you are looking out for yourself. While asking people about their personal experience, there can be a flaw with that method as well. Not everyone has a knowledgeable background with automotive repairs, it's impossible. There are mechanics out there that are aware of this and take advantage of that situation. They may seem like your best friend, pretend like they are giving that customer a break on a repair, but it can be just a dishonest business practice. Furthermore, this information is then based onto another potential customer such as yourself. Someone thought they received great quality service, but in the end they did not! It's normal human nature to have that trust in someone who presents themselves as a professional and has a business image to maintain.
The next method is using the internet which most have access to. If you are able to find your way around the internet, you can either search for reviews or automotive forums. Online reviews can be found on automotive forums, Facebook, Google, Yellow Pages, Better Business Bureau, etc. People can post their personal experiences whether they are positive or negative. To go a little more into depth on automotive forums, they are large a community of members that are located throughout the world, but there are instances where you can find members locally according to your geographical location. They can consist of being generic or manufacturer/model specific. When becoming a member of automotive forums, you are able to either search for local reviews or ask people's recommendation/opinions on local repair facilities. And on the plus side, automotive forums tend to attract more individuals with automotive repair experience/knowledge which provides more of a solid review.
As for my last point which I personally find the most effective. This still isn't a foolproof method and you are not able to avoid that untrusting repair facility, but it at least reduces the risk for someone to take advantage of you. This can be done by doing your own homework on the repairs or issues regarding your vehicle. I do realize that not everyone has the time for researching or taking the time to understand the mechanics of a vehicle which can be a complicated subject. But using the right resources, it can be significantly easier than originally thought to be. From my personal experience, one of the best places to seek information online is car forums. A car forum is an online community where either enthusiasts or people such as you can create a profile and are able to interact with each other around the world. Some forums can either be manufacturer or model specific such as mentioned above. Obviously quality will vary between forums and this can be relating to how user friendly the site is, what previous information has been discussed in the past, the knowledge or personality of the members, etc. It is a good practice to become a member and search through the history on those particular forums to seek answers for your particular vehicle issues. If you are not successful from a simple search, than go ahead and create a thread giving as much information as possible about that particular issue, along with a little relating history of the vehicle which may have affected the current problem. Depending on how active the forum is, it can take anywhere from five minutes to a couple days for someone to respond. Most people I do find are very helpful assisting others in need or at least leading someone in the right direction.
After discussing through all the methods, in the end of your searches I would personally recommend my last method by becoming a member of a car forums and interacting with others about whatever that issue maybe at hand. Car forums are filled with hundreds or thousands of others member owning the same or similar model of vehicle. With that being said, there is a very good chance someone else has experienced the same or at least similar scenario and they may be able to provide you with some insight. It is beneficial to you being one step ahead of the game, remember knowledge is power and this reduces the risk of having someone take advantage of you. Investing this time for your wallet and your vehicle, you are looking out for your own best interest. In all reality, you have to go through the experience of dealing with a repair shop yourself. It is the cold hard truth and I don't want to go around candy coating the matter.