An Italian tuneup usually refers to a process whereby a motor vehicle engine is run at full load for extended periods in order to burn carbon buildup from the combustion chambers, spark plugs, and exhaust system.
Apparently there are different ways people do this. My commutes around town are short (like 2 miles one way) and my automatic usually shifts around 2k rpm, low rpm stuff my car mostly sees. So Italian tuneup is perfect to do once every few weeks, I think. Top Tier 93 octane gas also has detergents that supposedly clean the injectors and such, so that's a plus.
What I do is go to the usual back roads location and simply do a bunch of 2nd gear pulls until redline, maybe a 1st-2nd pull, and let off each time (don't want to be caught wayy above the speed limit). There's even a tight corner section with some elevation changes, so I floor it in 2nd during the short straightaways and let off coming into the corners, which slows the car down without the use of brakes.
Edit - here's the tight corner section (my video)
I've read of people cruising on the highway with the rpms above 4k rpm for around 10-15 minutes, but I'm not too sure about that.