While we're at it, plural of "Healey" is "Healeys". That's right, no apostrophe. Plurals are made in English the vast majority of the time by adding an "s". (Horse, horses). Sometimes by "-ies". (Pony, ponies). Sometimes with something else. (Elf, elves). NEVER with an apostrophe. Apostrophes are for possessives or contractions.
Possessive, that is the "seats of my Healey", is "Healey's". ("My Healey's seats"). If you have more than one Healey, it's (contraction for "it is"!) "Healeys'". (My two Healeys' seats).
Contraction for "Healey" "My Healey is running great" is "Healey's" as in "My Healey's running great".
Done.
Worse than "Healy" in my opinion is "Aston Healy". Almost as bad is (OT) Alpha Romeo or Alpha Romero (used to love that one when I owned a '71 1750 Spider).