An overall fun game as long as you don't expect any depth. Not sure what previous reviewer meant by the interface, but I found it easy to work with, however you don't buy a game for the interface; instead, you buy it for how well it plays.
Good: The Wii controls are fun. Drag racing is simple and enjoyable requiring you to hold the Wiimote directly towards the screen, "popping" the Wiimote down to shift quickly while holding the gas with the "B" button. In normal racing you hold the Wiimote sideways like a steering wheel and turn it to steer, which I also found quite fun with a good accuracy. Graphics are pretty nice, physics also seem fairly realistic when breaking and turning.
Bad: Upgrade options for cars are a complete joke; case in point, say you want an engine upgrade and can only afford a Stage 1 upgrade, well you get three choices yet all three choices cost exactly the same and offer no difference in performance between the three. The same goes for every single upgrade in the game, different product names but no difference in price and no difference in performance other than Stage 1, 2, or 3; quite ridiculous.
Also, while we are on the upgrade portion, they spent a ridiculous amount of time allowing you to customize the look of your car (which could be good to some people,) for a non-multiplayer game which could, and should, have been used to actual performance modifications. Actual upgrades are overly simple, you can't go in and upgrade something like your cam or clutch plate. Also, all upgrades ONLY effect one of three tiers, so don't expect any particular upgrades to, say, improve shifting times.
Damage modeling is very weak, at best. Don't expect to see any bumpers dragging or dented body parts.