Looks like you buggered up your veiws and settings, my advice, turn off 'simple track', this can be found in Options>Graphics, Near the bottom. And try to set 'default driver view' to in-car, this can be found in Options>View. Also make sure you have not pressed the 'f' button in-game as this shows wheels only. To change view in game press the 'v' button. Also if that doesnt work try setting 'track LOD reduction' to no.
Hope it helps.
Wolfy