Is it really necessary to "break-in" a Prius? I bought my 2004 a few days ago from a dealer more than 100 miles from my home and drove it back at an average of almost 80 mph (a combination of glee and curiosity motivated the speed). I almost never came near flooring the pedal, but after reading the owner's manual, I have been more delicate lately and am driving very conservatively. There are two distinct schools of thought about automobile breaking-in periods. Some mechanics swear that if you drive slowly when the car is new, the ultimate top speed will be reduced. Others swear that the life of the engine will suffer unless you allow the pistons to "seat" properly. Have I done permanent damage to my new car or is the "break-in" period just a precautionary ritual? By the way, after driving a series of Jaguar XJ-S's for 17 years, and anticipating considerable compromises when I purchased the Prius, I am pleased to report that I have had the time of my life behind a wheel these past few days. The 2004 Prius is a joy.