This is something I have always wondered: Car names like Lotus, Lexus, Stratus, etc. Is it Lotuses, Loti, or Lotus (like deer or fish, plural is the same) I would say the singular and plural are the same, but does anyone have an opinion?
Audii... hmmm. Porsches, Lamborghinis, Lotuses, Ferraris, Aston-Martins, Volkswagens, Audis, BMWs, Rolls-Royces, Bentleys, Morgans, Jaguars, Nissans... Lexus should be Lexuses, even if it sounds weird. I'm an editor and use Associated Press (AP) guidelines. Usually you stick an 's' at the end, unless (like Lotus) grammatical rules require an 'es'. You're not supposed to change the spelling of the proper name when you make it plural.
Wouldn't it be Lexi, Loti, Starti, Airbi? Edit: But as said above, I've always learned to add the S for proper names. I only say Foci instead of Focuses because the word focus came before the car.
Focuses is correct. And it's also a real word. The problems with 'Foci' are (1) it changes a proper name - a capitalized name of something - into another word, against style guidelines and (2) guys without degrees in English will knock you to oblivion if you start talking about your Foci in a bar.
This is correct. The spelling of the official names cannot be changed. An "es" must follow to represent a plural.