I got a new Elantra about a week ago, it currently has around 300 miles on it. This weekend I have to take a trip of about 400 miles each way, mostly highway driving. I know the owner's manual says to keep speed under 55 for the first 12000 miles, but this seems a little extreme to me, even when I test drove it the salesman insisted I take the speed up to 65 to see how it feels. By the time I actually leave on this trip I should have about 500 miles on the car, is that an adequate break-in to be able to drive at highway speeds without doing any damage to the engine? It hasn't used any oil and I'll stop and check it during the trip, but it certainly wouldn't be practical (or safe) to stay at 55 on the Interstate! Any opinions appreciated, thanks.