You will receive the following rewards from completing the Final round of Grand Prix™ Events:
Reputation (if currently in a Club)

The number of rewards you get are based on your final position as well as the tier you had selected. Higher tiers of difficulty yield better rewards.

Asset rewards will range between the following Series for each tier:
Junior - Series 1 to Series 3
Challenger - Series 1 to Series 6
Contender - Series 1 to Series 9
Champion - Series 1 to Series 12