Vivissime felicitazioni.
Come grammatica e` corretta, cioe` un aggettivo segue il sostantivo che e` 'auguri'.
l'augurio: singolare,
gli auguri: plurale
I think you thought 'auguri' as a verbal voice, not in this case.
The accent is like this: augu`ri
If you say like this: a`uguri, you get a different meaning, like prediction of the future, and the meaning of 'wish' disappears.
You can get the meaning of the word 'augurio', 'auguri', thinking of the
complete sentence (that we don't often use) :
Ti faccio {un augurio, vivissimi auguri} di ABC .
English:
I make {a wish, lively wishes} of ABC
Using the verb 'augurare' you could say:
Ti auguro di ABC
which is good, but it usually used in special circumstances, as when a son
leaves from his family to follow his own path, in this case, for instance:
(father,mother to son)
Ti auguro di trovare e realizzare la tua strada, figlio mio!
So, at least from this example, the context is 'dense of meaning' when you use 'ti auguro', (verbal voice).
In lighter situations the noun is perfectly ok.
Was this actually your doubt ?