Hi,
You can change how to load other player's car who join an online session in the mutliplayer options menu:
-in box: As Gee-Dee said you have to come back to box to load the cars
-safe speed: load the players when your are driving slowly (about 20 km/h, this speed can be changed by editing the configuration file of the game). As there is a small freezing during loading (depends on your computer preformance), it helps not to crash. It permits to make the loading without coming back to pits, I use this option.
-any speed: load the cars whatever is your speed, I tried it but it's quite dangerous when there is a freezing while you are running at top speed or in a fast corner. Perhaps it works fine with a very powerfull computer.
Hope this helps.
Tonio.
I'm French so sorry if my English is not perfect
