Musical Instruments And Accessories

I called a local Infiniti dealer (I didn't purchase the car at this dealer) and was told that the service would cost $275 and the new part would cost $850 [total= $1125]. I then found a shop that replaces glass in cars and they told me my windshield replacement, with the part and service included will cost $140 total. I don't know whether I should get my windshield replaced there for 2 reasons: 1) They might do a poor job and not glue it on properly, or well enough, so that it might start coming apart from the frame of the car in several months, and 2) rain may leak through (because they are doing it for a lot less that Infiniti, I expect the result to be a lot worse).

Am I right correct in my assumptions? Should I get my windshield replaced with the generic place or should I take my car to an official Infiniti dealer? Can I trust the generic shop to do a good job on my car? Any help would be appreciated greatly. Thank you.