Picked up a new 05 Elantra GT last night. Drove it straight home on secondary roads as it was late and needed to get a late dinner going. This morning I got it out on the parkway....After the morning rush thinned out I finally was up at 60mph.....Needed to stop firmly <not panic or even Hard> And the Damn brake pedal starts pulsing and I get a bit of front end shudder, which continues till I drop below 35mph. Freaking annoying as at this point car has 100 miles total on it. Took it back to the dealer and told them I needed new rotors.....The symptoms were pretty obvious. Three hours later I got the car back with new rotors and took it on the highway to test it...So far so good. But what is a possible reason for rotors to be bad on a brand new car? Is there a problem within a related system that would cause this that I need to watch for? Through-out this I surprised myself by staying calm and not trying to rip off some heads. Andy C