Was the army of the Hundred Days already mechanizing?

Was Haig's army practicing early mechanized warfare by 1917-18?

The reply calls it an early development and identifies the Hundred Days as the clearer example.

Mechanized warfare in Haig's forces is described as a very early development, with a more definite case made for the Hundred Days in 1918 than for 1917. Artillery tractors, motor transport, and armored cars provide the examples. They illustrate a changing system of movement and support without implying that the whole army was fully mechanized.