If buying second hand, make sure you clear any saved games; one needs to progress through the game, to appreciate it more. The best thing about this game is the graphics which become blisteringly quick later on, and gradually throughout using nitrous boosts. There is story, which I have ignored, and only do essential upgrades at the end of each major level (city part). It might be worth spending a bit of time doing upgrades which benefit your overall score.
The tracks can be quite good too, but what is the greatest weakness is the ease in which the game is completed. I will have completed it in about 3 weeks at about 20-30 minutes a day. I am sure some will do it quicker. I realised too late in the game that what appears to be an opponent is a wingman (which presumably is someone on your side), a nice concept but I think they cause me more bother than help. If you race and avoid crashing within 10 seconds of the finish line, you will always win it seems.
Ignoring back story and opponents this is still an exciting game just simply to race and come first. Its years since it was released so one should be able to get it cheap and then move it on. I got mine cheap and will keep it to revisit in a few years time as I love racing games. Nothing will match Mario Kart as an all round racing game, but this one does have ultra-realistic scenery for its time.