Truck concept design

This is the first vehicle project done to enhance a efficient and a quick workflow to create, from cero, a vehicle concept... Was done a few weeks ago, so fun to work with, my time in this one was not the best but was ok by now. My modeling skill is still very raw, but was enough to create a massout to follow. There are a lot of things to improve yet!! Do you have an advise? let me know in the comments please!