The famous 'V' shape at the front and the split windscreen are undoubtedly the two features that make these vehicles so identifiable. I've tried my best to recreate both, using the studless see through 1x2 bricks to angle the windscreen slightly and the 1x1 slopes to create the 'V'. Along with this and the placement of the headlights and badge I don't think the front looks too bad, but please let me know what you think! Going for a 5 stud wide body has allowed me to shape the front and rear end a little better. The bumpers have been fashioned out of Technic pneumatic hose with a bent paper clip inside so they hold their shape.
Couldn't decide whether to use a 1 x 2 tile upside down in the rear wheel arch instead of 1x1 slopes to better emulate the flattened rear arch of the real thing. In the end I liked the use of the slopes so they stayed!
Although using the train/plane windows means I can only fit three in as opposed to four, I think their shape captures the look of the real thing perfectly.
A comparison of a scale model and my minfig scale Lego model