There are several faster cars than those that Ferrari makes. Bugatti and Maclauren both make cars that are faster. However Ferrari cars are quick and they do over very nice styling. They might make the fastest type of a specific car, like a Formula one car, but not the fastest car ever.
Ferrari's are some of the most dynamic, and sleek looking cars there are on the planet. They are extremely fast and look good doing it. However they are not the fastest car in the world. Lamborgahni has a few cars that are faster, but I would rather have a Ferrari. They are amazingly fast just not the fastest, however I think they look the best.
Currently the Hennessey Venom GT is the fastest car in the world with a top speed of 270.49mph, Ferrari cars in general are very fast cars but overall many luxury car markets similar to Ferrari have designed their cars for performance as well so I don't think I could consider Ferrari cars to be the fastest in the world.
I once saw a car that transforms into a plane. In order for a plane to achieve lift (fly) it has to be traveling faster than any car including a Ferrari could travel. Although a Ferrari is probably the fastest car in the world, there are alternate versions of cars that do in fact exceed the speed a Ferrari can travel.
While Ferrari cars are some of the best and fastest cars on the planet Earth, they are not the fastest. I think that there have been other cars that have clocked in at faster speeds than the Ferrari. The McLaren is one car I can think of that had a faster testing time.