You'll automatically unlock Bullseye at the end of the 11th race on the Game
Map: Scrapper's Run
Circuit: Semi-Pro Podracing Circuit
I had a hard time on this track but changed to Ebe Endocott and he made things easier, just slow down after the second jump to avoid crashing, if the first place surpasses you I'd re ommend restarting the race, he's too fast to catch up again.
There's game commands to unlock everything in the game, check the following solution