As a group, it can be difficult to pass a slow moving car on any road with two or more lanes of same-direction traffic. This is especially true with moderate to heavy traffic. Often there is not enough room for the entire group to get between cars in the faster lane.
The way to accomplish this is for the last bike to pull over one lane to the left and hold his position. Each rider should move to the left lane as the cars in front of the rear biker pass them. You can then pass the slow car as a group after the lead rider moves to the left lane.
The lead rider should move back to the right lane after passing the slow car by a safe distance. It is very important that the lead rider maintain speed to make room for all the other riders. Each rider should move back to the right lane one at a time once safely cleared the slow car. This can be a real slick choreographed move for other motorists to observe.