I just tried the game, and did a little cup.
Graphics wise, the game is better in motion than in the screenshots, altrough, their is some slowdowns.
The cars are well modeled and can be damaged.
The environement is...sometines relatively nice for a wii game, sometimes quite bland. Trees and bush are quite bad IMO. And I think they look quite small. Textures of the road or rocks are pretty low-res and smoothed a lot (which give it a n64-ish feel).
Control wise, I did not liked the wiimote controls, so I pluged my classic controller, and put the "Pro" controls. Controls are like other Dirt/Colin Mcrae games, it takes a little time to master the car.
Sounds in my opinion are annoyning, and their is no "in race" musics (only in menu).
Overall: It's not as shitty as you can think of by viewing the screenshot. Give it a try. I would not say its a good game, but definitively not a crappy one. After 30min, I could say it's a average game worth giving a shot who will last for some weeks then we will forget it (sadly, like many wii games).