I'm with the last couple of posters. I think you're making a big deal out of what occurred. They made a mistake, admitted to it, fixed it and then gave you $100.00 off.
Why didn't you install it yourself? The answer is because it a difficult job. I just did one last week for a friend and went through a dozen drill bits trying to drill the mounting holes through the spring steel bumper insert.
I doubt that they drilled a hole in the transmission line so that they could aggravate you.
I would be upset about it, but work it out reasonably with the dealer. I'm guessing you're talking a little tougher here on the forum than you did with the dealer, because if I were the dealer, your attitude would have shut me down and not offered anything back, but your finished car.
