For the true, die-hard, obsessive import/automotive enthusiast.
The game is very long and will probably take you a week or so to finish, if not more. Also adding to its longevity, is the huge amount of Japanese, American, and European cars to unlock. With everything from the Trueno and Levin, to the R34 and EVO V, they have just about every sporty car that has been released in Japan, as well as some interesting ones from overseas such as the Viper GTS and Beetle RSi.
Also, once any car has 1252 miles on it, you unlock engine swaps. Now THERE is some fun stuff. Who doesn't want to take, say, and RX-7 and drop in a V6? Or an MR2 with a V8 Turbo?
The sound is rather lacking, with the engines not sounding all that strong, and the music becoming rather grating after a few hours.
All things considered, TXR3 is a very good game, especially for its current low price. The amount of cars and tuning options will keep anyone with an automotive intrest busy for a VERY long time.