With the low poly count and low-res textures I would think they could render just about any object to infinity with the resources of the Dreamcast, so I can only blame a shoddy graphics engine for this problem. If I didn't know better I would say they ported the PSX version rather than the PC version - hey, maybe they did. Track design is equally as bad. There isn't much that is challenging about any of the tracks. Most are only slightly wider than your car so you are unable to pass, and since physics is non-existent you will spend much of your race bouncing off the walls or invisible walls if real ones aren't available.
Cars are equally horrible.
If the polygon count were any lower they may as well use sprites. For the money they obviously spent on licensing these exotic rides you think they could at least make the game cars look like their real-life counterparts. The jewel case touts their new Auto Paint System, but the cars are generally a solid color with no reflections or metallic look to them at all. Sound and music are excellent but only good enough to get this game the half a star it received. Infogrames apparently decided to follow in Grand Turismo's footsteps with the premise that great music makes a great game.