I don't know if I'm being thick here but I'm missing something as I can't see any difference when I select practice session in the setup apart from an x in "practice session" box at the bottom of the main screen - when I click start I go into a normal race which stops after the number of pre-selected race laps. Also, the x is still showing in the practice session box and clicking on it doesn't change it.
In short what I'm looking for is an unlimited free practice mode which shows lap times