There exists a 3D version of Mario Kart Wii

[TomaTito]

Galaki said:

Elsewhere in the interview, Konno revealed that the system's gyro sensor, which is used heavily as an optional camera control and aiming method in many games, was added particularly late into development. They didn't decide upon including it until before last year's E3. This was actually after the specs had been finalized, meaning adding the gyro sensor would be difficult. However, Miyamoto said such things as "it feels like it's missing something," and "if there were a gyro sensor, the play could change greatly."

Gyro added in the last minute? No wonder there is no digital compass.
It would have been a simple upgrade from the DS without it...