Tightly focused, well-designed, beautiful graphics - one of the best WiiWare games by far.
Apparently, the game was influenced by classics like Micro Machines, and while the game certainly keeps the integrity of that classic gameplay in place, it also has a number of innovative features that make Hot Rod Show an absolute blast to play. The game is based around a boosting/stunt system that provides blistering (and for a Wii game - not just a WiiWare game - beautiful) gameplay. For seasoned kart racers, the easy and medium difficulties are a little too easy, but the hard level gives just the right amount of challenge.
Multiplayer is an absolute joy, and a really nice feature for a downloadable game. Hot Rod Show also gives you several control options: the Wii remote all by its lonesome, the remote and nunchuk, the classic controller, or the Gamecube controller. All of them feel just right and the Wii remote combined with the steering wheel gives a really fun and surprisingly tight control combination.
There are a few small issues - you'll occasionally do more stunts than you mean to, and the blooz-rock soundtrack, while enjoyable for awhile, gets a little bit irritating. But these are really tiny compared to the rest of the game, and are easily overlooked.
All told, it's really fun. There's only 6 courses, but the multiplayer aspects and sheer giddyness of the game make the game well worth $10.