This business saved me over 1000 bucks. My mercedes c220 failed smog at another location. I took it to my regular mechanic 3 times and he couldn't diagnose the problem and finally proposed a 1500 dollar fix. I felt I needed a second opinion and took it to Water Star, because I wanted a certified smog repair mechanic familiar with the Benz.. They charged me 150 or so to go over the car and diagnose the problem. And Lo and behold they, they correcty diagnosed the problem as a cracked breather hose, a relatively inexpensive part!