INFINITI of Denver

My service manager is fantastic but I have had continued problems with the car itself. The car was a Used / Certified Vehicle and I bought an extended warranty so I have not been financially hurt but the amount of time I have spent on the subject is becoming unacceptable. My feelings is that the certification process wasn't completed very well and the car was rushed to sell. Again, I appreciate all the help and timely communication but it has been frustrating having to deal with a tire pressure valve that wore out (5 visits), Issue with my roof rack and the rear door catching on the roof rack (2 visits), my front tires making a strange noise thus going to discount tire and them telling me it has do do with the Wheel. I took it to the already scheduled appointment I had for the roof rack and told them there is an issue with the front wheels and it resulted in replacing a major replacement of the front axil and bearings on the wheels. Had car back for 1 week and the rear differential ceased on the highway (while driving 65 miles an hour) and it felt the car exploded. Had car towed to dealership and it was fixed quickly and the technician test drove it and the service manager took it home for evening. I trust that the problem is fixed and have faith in their work. I hope my trip this weekend to the mountains will not be disrupted by more inconvenience on a car issue.