Differential Unit problems of the 2005 Lexus RX330

I am having serious quality problems with my 2005 Rx330. The vehicle is kept in the garage and being taken care of like a family member. I took the SUV to a Lexus dealer for routine maintenance and was told that the stearing column was leaking and need to be replaced - approximate cost $1800. I was also told the front differential was leaking and need to be replaced - cost another $1000. This is not the end! approximately six months ago my water pump failed at the middle of a busy intersection, and I had to replace my water pump, timing belt, drive belts, etc only at 65k miles - cost $1200. Why every major key components are failing so early? I drove a car made by a competitor upto 110k miles without any of these issues. Lexus/Toyota is using defective/cheap parts at the expense and safety of consumers. I would recommend starting an investigation against Lexus/Toyota for faulty steering and power train components in RX, and based on the investigation, start a recall if needed. I reached out to Lexus in the past, but they don't acknowledge any quality problems with Rx330; however, when I searched the internet, I see hundreds of owners have the same issues and they are helpless. Lexus will not do anything, and therefore, we need NHTSA's help to push Lexus to recall Rx330 steering and power train components.