There are two hidden tracks in Sonic Racing: Crossroads, and if you haven’t completed any of the earlier tracks, then you would find them locked from the start. One of the hidden tracks offered to you is the Secret Grand Prix, which requires several requirements to unlock it. This guide will detail how to unlock the Secret Grand Prix in Sonic Racing: Crossworlds.
Unlocking the Secret Grand Prix in Sonic Racing: Crossworlds

To unlock the Secret Grand Prix, win first place in each race across all seven Grand Prix. Unlocking all 6 tracks unlocks the seventh race, the Egg Grand Prix. Next, work on obtaining first place on all races, which unlocks the Secret Grand Prix. Only after achieving first place, including the Egg tracks, will the Secret Grand Prix become available.
In short, focus on completing every race to unlock all tracks, then aim for first place in every Grand Prix race—including those in the Egg Grand Prix—to unlock the Secret Grand Prix. Our tip to help you win all the races quickly would be to use the High Speed mode to zip past competition. If you wish to redo a track, then shell out 20 Donpa Tickets to redo it and get the perfect score.
About Secret Grand Prix

The race themes for Secret Grand Prix include Kronos Island, Northstar Islands, and White Space, with the fourth race being a mashup of all three tracks. Sonic fans would notice these race tracks as familiar, since they are modeled after previous mainline Sonic games.
Successfully completing all of the race tracks for Secret Grand Prix unlocks a new skin for Sage called Dark Sage. Plus, you also get to view a special credit screening at the end, which features several past Sonic games and their respective theme music.
Now that you know how to unlock the Secret Grand Prix in Sonic Racing: Crossworlds, why not get a head start and try your luck winning races against your friends?