The Data Logger is technically a returning feature. In GT3, you could load replays (I think only the "best lap" / ghost type, not sure) and view inputs and physics readouts in real-time, and watch the car in slow-motion etc. It also allowed comparison of two different laps, using separate traces and the usual ghost visualisation in the "replay window". I think the Data Logger returned in a later game without the 3D imagery, and was slightly less flexible.
If the
Data Logger referenced in the blurb for the
1.06 update is the same thing, then there is no issue regarding sources of data at all.