The first 100 miles

JARblue

Generally I tried to push it to about 5.5K in 2nd-4th (4K or so in 1st/5th), but I was putting in the clutch as soon as I got there and then letting the RPMs drop all the way back to almost idle levels while in neutral. Then I revved back up to appropriate RPM for my speed and made my next gear shift. I also made sure to downshift into just about every gear except first (although you can do it easily with SRM). The key to this is being very steady while you traverse the RPM range for each gear. For break-in period, the SRM can really help since it can make every shift smooth as butter especially if you need a little bit of a learning curve.

And I'm not saying that cruise control at 60 is bad for your engine during break-in, but getting the engine to go through the lows and highs in each gear is the proper way to break-in. If you find that most of your break-in miles are cruising on the highway, you're not truly breaking it in. In that case, I would recommend using the frontage roads every once in a while, or just take it around town every so often for 30 min of driving where you make sure to do some proper break-in.

FWIW, every mechanic I know says this is how to break-in properly, but they never bother to do it to their own cars...