I want to buy a very fast but cheap car?

Which one is the fastest, Honda Fit, Ford Fiesta or Toyota Prius?

Skoda fabia trumps all

I would go for a Honda.

They are ALL "fast" enough to get you a speeding ticket if you drive over the posted speed limit. That's all you need to know.

You can get a brand new 160 mph 600cc street legal racing motorcycle for under $15K, out the door.
It is trivial to find a used 160 mph 600cc street legal racing motorcycle for under $5K.

None of the above.

None of those are very fast. Just very ordinary in terms of speed and acceleration.

A Barbie car.

Your idea of "… Very fast…" is clearly different to the rest of planet earth…

None of the above. You would need to get into a Honda Civic or Mazda 3 if you want good quality and at least moderate speed.

If you think THOSE are fast, I'd hate to see you in the passenger seat of a car that's actually fast…