Columns (Forza Horizon 4)

No matter how much I go, it's always other players go in the columns (the icon of two cars next to the nickname). Went with a friend, but he is not always in the game and I don't play all day; and to compete with bots tired. I propose to add a column to counter players zero response. There are still some ways to drive in the company (to be added in columns or to be added to the group)? Who can use it and explain how it works?
Multiplayer is different, I asked specifically about the column. And that begins to bore the game to be honest. Race took (and time), with bots the same ride little interest.