"a" and "an" usage

[Unregistered]

In writing about a specific item and quoting it's name, does the vowel sound still take precedent or if the name is in quotes does that remove the quoted name from the sentence structure and defer to the word following the quotation marks?

Example:
An "Additional Vehicle" pass is required.

or

A "Addtional Vehicle" pass is required.

Which is correct?

[it s me]

In writing about a specific item and quoting it's name, does the vowel sound still take precedent or if the name is in quotes does that remove the quoted name from the sentence structure and defer to the word following the quotation marks?

Example:
An "Additional Vehicle" pass is required.

or

A "Addtional Vehicle" pass is required.

Which is correct?

A or an depends on pronunciation and in your examples the word "additional" requires an considering its pronunciation and quotation marks have nothing to do with its pronunciation. :)
Hope this helps :)