What's the difference between "es" and "está"? When do I use one above the other?
For locations, you'll always use está. If you look around the discussions you will find heaps upon heaps of topics about the differences between ser and estar (the infinitives of es and está).
Why is this wrong?
"Donde esta el negro coche?"
There are 5 accepted versions of car in Spanish. carro, auto, automobile, coche, and guagua. Mine was counted incorrect because I used guagua, it is correct however it is used predominantly in Caribbean version of Spanish.
"Automobile" is incorrect