There's no single number for how many different car *models* have been invented. Thousands upon thousands of car models have been produced over the history of the automobile, by many different manufacturers, with countless variations and iterations within model lines (e.g., different years, trim levels, etc.).
It's also difficult to define what constitutes a distinct "invention." Many cars are evolutions of previous designs, rather than entirely new inventions.
Therefore, a precise answer to your question is impossible.
