How about to create a 2 separated leaderboards?
The first one, what is counting the solo bests, records, times only.
The second one, where the leaderboards is counting the scores with the crew only (boosting session).
I believe its really wise idea.
People here are trying to do the bests! But sometimes players want to do it in crew, where the records might be better, like the racing ones (slipstreams/draft, Demolition Derby and I believe much more!)
so then people should feel fair, that someone did better time in solo, but also compare to the boosted one with the crew,
Im an professional player from NFS series. Now the leaderboards are sometimes really difficult to fight with, bcs in some events the boosting sessions are helping a lot!