[Spaceywilly]

The car uses port and direct injection while the engine is warming up and switches to DI only at some point. No idea about the 300 miles part, probably just parts of the engine breaking in. The high pressure fuel pump runs off the crank shaft and uses engine oil for lubrication so I'm sure there is a break in process just like the rest of the engine. One of the few times I heard it was when I was showing the engine to someone, it had been on for a minutes already, and I heard an audible click and then it started making the chirping noise. I assume that click was the engine switching to DI.