how much mileage is considered as "broken in" ? Mine is on it's 4000 KM.[/QUOTE}
As for when a new car is broken in, depends on a lot of factors, including the car, the driver, the type of driving done, and factory reccomendations.
Motorcycle mantra is "Break in fast, goes fast; break in slow, goes slow".
In reality, most moving parts should be sufficiently free to rotate as smoothly as possible by 10,000 km/6000 miles, but mileage could continue to improve over time as long as the car is kept in perfect tune and driven consistantly.