Like with the Official Arcade Stick, the official Dreamcast steering wheel was not actually produced by Sega but licensed to Agetec.
Initial thoughts when coming across the controller is that it feels well-built, sitting sturdily on your table/desktop and the A and B buttons are well-placed towards the middle of the wheel within easy reach, yet hard to brush against accidentally. There is also a VMU port conveniently located to the side for game saves but the wheel lacks any vibration function. As there are no pedals, two wide triggers behind the wheel are used for acceleration and braking and they feel very resistant and allow you to make subtle inputs, although it's pretty much the same as holding down the triggers on the regular DC controller
The main problem is that the wheel itself has trouble registering subtle movements. In all of the racing games you find yourself having to adjust the response settings to max just to give yourself any chance of not swerving off the road. This unresponsiveness also makes navigating in-game menus a real pain; maybe they should have included a D-pad like they did with the the Dreamcast lightgun.
One additional thing to mention is that the Japanese version of the steering wheel features a small socket on the rear, similar to the inputs found on the Samba De Amigo base unit, and it is believed that this was originally intended to enable future upgrades such as a foot peddles or a gear stick (thank you CD Ages).
Overall, the Official Dreamcast Steering Wheel is probably one of the weaker accessories from the official Dreamcast peripheral lineup. Steering wheels are supposed to give you better control in racing-type games and heighten the gamer's immersion. However, the Agetec steering wheel handles far too poorly, and while the build quality is respectable, it is really hard to recommend something that offers little advantage over the standard Dreamcast controller.