What kind of rewards can I expect in Team Races?

You can receive multiple rewards in Team Races as highlighted below:

Lap Rewards: They are based on the number of laps your team completes. Every team can get a brand new monster, its cells, Avatars and Chests after completing a certain number of laps. Rewards depend on your team’s effort.
Position Rewards: By earning a higher place than the other teams, your team will win Monster Cells and Seasonal cells like Nectar and Ambrosia.
Individual Rewards: Team members with more than 300 points are qualified to get individual rewards like Food, Cells and Relic chests. Rewards are proportionate to your contribution in the race. The more you participate, the more you can earn.
Grand Prix Laps Challenge Rewards: Teams with the most laps get additional rewards like Heroic orbs and Seasonal Cells at the end of the Team Race.

Note:

To qualify for rewards, your team will need to complete the minimum amount of laps required.
Switching teams after the first half of the race will prevent you from receiving any team rewards. However, you will still be able to contribute to the team and get individual rewards.