Extremely flawed and ridiculous
Ok, think of it this way; try to imagine what an idealised world of street racing would be like through the eyes of a testosterone pumped 16 year old boy, and then add bad acting, terrible sound effects, dated graphics, and a totally unrealistic physics engine. There is only a limited number of cars available, and a very restricted number of parts. Most of the bodykits and wings look terrible (note, there is only one kit per car!) and often the statistics on engine HP etc do not correlate with what is actually given.
About the only positive thing about the game is the inclusion of a "dyno" that lets you see the power/torque curve of your car, which changes depening on what parts are installed.
Any of the more recent Need For Speed series can give a much more enjoyable game, and are probably more realistic too... And that is saying a lot!!!