I started pushing it around 750 miles. Car is fine, although it does seem to vibrate a lot while idling but that's normal :P

 

I believe the key is smooth driving along with an early oil change the first time.

 

I always follow a slow and smooth break in for the first few hundred miles just to get the transmission and other specific mechanical parts worn in properly. But that lasts only a few hundred miles, after those few hundred I'll start driving it like I stole it. At about 1500k I'll switch to synthetic oil and reset the ECU to relearn my REAL driving habits. Did this with my 05 FX (now has 100k miles on it and is driving like its brand new still) and I did this with my 08 g and its at 30k now still driving like its brand new no problems.

 

Well first off most are 'somewhat' broke in when they arrive compared to the old days.

But I still drive mine easy for the first couple of thousand changing the oil early the first time and then drive it normally after that. I typically get about 200 k before anything major will show up and have had many towed away simply because a cheap fix isn't cheap enough for the car. My last one I had towed away at about 315k with a bad rear axle bearing which occurred about a year after it went under water on the way to work during a flood.

I think one of the important items is to change the oil early. A typically filter really doesn't hold all that much and it is possible for things like gasket sealer etc. to be present. The oil can look clean with a dirty filter and one would never know it.

You also mentioned something I consider important and that is most often people mention the proper way to break in the engine when there is the transmission, the differential, even the brakes to consider.