I've used these rules in other racing games and applied them to Moto Grand Prix for two races. I think they work well and fit the theme of team racing.
1. A pawn that has completed its turn may move out of the way of an oncoming pawn. In this game the first pawn may move sideways to an empty space to allow a team mate to pass thru. The sidestepping pawn must remain in the space where it sidestepped to, it may not return to the original position after his team mate passes thru.
2. Team mates may occupy parallel positions without contact if there is an empty space between them.
Use these rules in your game if you like them. Don't use them if you don't like them. I won't banter and argue with you over the merits of these rules.