Steve raises an interesting topic. Warranty is something that consumers have come to expect, but have no idea of the costs involved. They are simply insurance policies, nothing more.
Steve does not want to buy into the "pool" as he believes that the insurance policy does not guard againt manufacturing defects, but ham-fisted installs.
I know many people that buy a new car simply to have a warranty. They pay no attention to the costs involved. I have bought new cars in my life, but acknowledged it to be an ego-driven purchase, not one of economic sense.
However, I don't know the costs involved. It's pretty simple to figure out the warranty costs on a new car. You take the price of a new car, the value of the car just out of warranty, and you have a pretty good idea of what you paid for the warranty coverage, less any warranty repair costs along the way.
With a water pump repair, I can't come up with an overly simplistic model in my head. You could do a proper analysis, looking at failure rates and true costs, but I have no idea of what that looks like.
Is this "warranty" a significant cost in the price of the part?
1998 C230 "Black Betty"