Maybe its just i'm a noob one, but i've created my first track and when in validation mode, I'll start running in my track and everythings got fine..checkpoint boosts etc. but when I arrive at the finish line, the car doesn't stop as long as the timer. I've made anything wrong? I' ve placed in air the finish block after a boosted jump.

One of my online friends have experienced the same thing. The problem was he had forgotten to delete an underground checkpoint. When it was removed it worked of course. Could it be the same problem you're holding?

Thank you! You're very helpful 'cause i've managed that the problem was the dual track with dual checkpoints