hey that's looking really cool. what are entering for the search field when you get these images off of google? i'd be interested to know . lol i thought you drew your own concepts , but i guess not. it's all good though! how well you can model it is what counts .
That is looking very good, here are some changes I think should be made, mainly the window area (im assuming you want to get it accurate to the picture).
That looks loads better, Now you should add more thickness and detach the glass area from the mesh i think, and if you havnt already, stick the handle bar things in, or whatever control system it has. While im alive you will work till you die! Muah.