This is the 6264th most frequent Spanish word.
audi
"Audi" is not a Spanish word; it refers to a German automobile brand.
The word 'Audi' here refers to a brand of automobile, used as a common noun to indicate a specific car brand.
Yo tengo un Audi rojo.
I have a red Audi.
Again, 'Audi' serves as a proper noun indicating the brand of a car, used to describe a specific item observed previously.
El Audi que vimos ayer era muy hermoso.
The Audi we saw yesterday was very beautiful.
'Audi' is used to signify a preference or desire for a car of a specific make in this sentence.