The humor in the Astérix comic books relies heavily on puns and play on words. This is very much present in the naming of the characters.
Since for example the old Gaul's names often ended in 'ix' and Roman names ended in 'us', the names for the characters are devised likewise.
Together with the clichéd ending of the name, a pun or play on words was also inserted.

Cétautomatix is one of the side characters in Astérix's village. He is the town smith/technician.
His name is a contraction of the French 'C'est automatique' + the aforementioned 'ix'. The name means 'It's automatic' in English.
Since the ride is themed around a chariot garage, they choose to link it to the technician of the village and gave it his name.