I def. agree w/ breaking in the car very aggressively. My first car was a 99 civic ex 5 spd (im gonna get crap for that...at least there was minmimal rice) I was beating on it w/ 20 miles on the odo. It def had a positive effect on the car before I even did an y work to the car I was beating kids in Si's hanging right there w/ GSR's..none of my friends could figure it out...Hell I couldnt figure it out. After I did basic bolt ons the car was freaky fast for what it was. My point is that I think this was because of the way I broke the car in. As far as longterm affects....well the car was a lease and lets just say w/ 38K miles on it I had a bad tranny,bent valves and lifters.