Vehicle Sketching 1

Spend some time in office sketching out vehicles based on reference book borrowed from the library.
Decided to do this kind of sketching everyday in camp to build up my visual library.
Playing with shapes and extracting out what is necessary.
Things to look out is the curves being used, the wheels, the windows as well as the overall form.
Not sure if I am doing the correct thing but well, gonna make an effort to do at least 1 sketching and 1 painting each day.