Business letter

[Liz AG]

I need to write a letter to motor vehicles. Which is most appropriate:
Dear Sirs, or To Whom It May Concern,?

Thank you in advance for your assistance.

Liz

[Ouisch]

If it is at all possible to find out the name of a person to whom you can direct the letter, do so. If not, "Dear Sir or Madam" is preferable to "Dear Sirs," because quite often it is a female who reads your letter. "To Whom It May Concern" is always the very last resort.

[Liz AG]

Ouisch,

Thank you so much. Everything you said makes sense. I felt that "To Whom It May Concern" felt cold, but didn't know if preferred. I've now used the "Dear Sir or Madam".

I appreciate your time and assistance.

Liz