So I didn't see a save for this so hopefully I've helped out a lot of folk, this save file should give you all the world stars by completing one more event on expert (it's nearly impossible to fail) by doing that it'll unlock the last character and maybe the triple star license, I've completed all GP expert and some Time Attacks are expert and the ones that aren't have been completed hard mode<br />
Now Go to Time Attack mode and select the bottom-right cup (this is a mirror cup and needs to be unlocked). Select Sunshine Tour. Select Sonic with the Standard Mod as your character.<br />
Now you'll have to beat the Expert ghost on this track. Whilst drifting stay as close to the inside of the corners as possible as this is key to getting a good time.<br />
Once you've beaten the Expert ghost you will be awarded the Achievement and Sticker.