Played this online last night for six hours straight. Group B cars. Simply awesome!
You see the other players as ghost cars or can turn them off if you prefer. I usually don't like ghost cars, but for rallying it works. Sometimes the carnage on Dirt2 was fun, but meh, it isn't the point of rally.
Reminded me a lot of the online races i had on Microsoft's Rally Challenge back in the days on xbox.
It's not the prettiest game, nor does it have the most detailed physics, but it's lots of fun!