How to unlock Dry Bowser in Mario Kart Wii

According to this guide ,

Rosalina: Get a “One Star” rank or better in all Mirror Mode Wii-Cups. Or if you have a saved game file from Super Mario Galaxy, you should win 50 Grand Prix races.

You can also get Rosalina by finishing a total of 4,960 races.

According to this video, there are 7 alternate title screens.

1. Mario with crossed arms, saying "Mario Kart Wii!"
2. Mario driving in his kart saying "Mario Kart, whee-ee!"
3. Luigi saying "Mario Kart Wii! (with the man Luigi!)"
4. Luigi in the same pose saying "Luigi Kart Wii!"
5. Bowser laughing maniacally
6. Peach driving her bike saying "Mario Kart Wii!"
7. Peach in the same pose saying "Peach Kart Wii!"