Had the ticking problem. When you would accelerate the ticking would tick faster with the speed of the car denoting that it was something internal in the engine.

I would be told the same that they couldn't duplicate the problem. Until I got fed up and got the service manager in the car and took the car and let it sit at idle inside an enclosed section with high walls that made the sound so clear that the service manager said "wow we've had this car come in for this problem 5 times and i had never heard this noise" and he attempted to replace the lifters and rocker arms 3 times then the 4th time they replaced the entire head of the engine and it still ticked. At that point, i lemoned the car and got a replacement.

And yes by the way they horribly scratched my right front fender's top section while working on the engine. It seems one of the mechanics had a belt with a big metal buckle that kept scraping on the fender as he leaned on the fender to fix the engine and on a black car it looked horrible. For the money people pay for this car they should at least wash the damn thing when they give it back to you from service like Mercedes does. They would always give me back the car full of grease finger prints on the hood and full of dust and dirt.