Feb 1931, Esso Gasoline Capital Service Washington DC, Test Brakes as Car Washed

Description

A February, 1931, Esso Gasoline, Capital Servicecenter. Washington
D.C. rear view mirror card.  The card
states you should
Test Brakes as the Car just washed.
Also, there is a line indicating your
gas tank needs a certain
number of gallons
so you should fill up with Esso gasoline.
What helps date the form is two items.
The form is dated 2-31 at the bottom and the phone number has only
four digits.
The card is 8 x 5 inches in size. 
The card is in nice condition with no tears or stains.
Please see the other vintage items I have listed on eBay.
Thanks for looking.