I have to input here. Even though I dont own a Lexus anymore.
Fair enough you have paid top $$ for your cars, and you do deserve great service. I really think Lexus does offer great service. Dont take it for granted thinking "I will never buy a Lexus again" only becuase of 1 or 2 bad issues. No other maker offers this type of service, picking up your car, giving you a loan car etc.
Fair enough about the example above about nareesh not calling back and the scratch, poor form, but comon, the window washer not spraying the windscreen? How hard is it to get out of the car and see if there is some blockage there? Most probably some moth *BLEEP* thats stick right infront of the nozel, use a pin to scrape it clean, 30sec job.
What would you like? Free tickets to the opera or something? They have given you perfectly good loan cars for your inconvinience.
I think if you buy a BMW or Audi, you will realise just how good lexus & their service is. I can comment in regards to Mercedes as I have had no experience with them.