Awesome! The shooting brake looks great!
I think one thing you can do to add a bit more realism to these is to add a bit of transparency and an indication of seats/pillars etc. it shouldn't take too long but will add a lot to the render
Also think that maybe the glass could have some more ground reflections on the side DLO and/or fade the cloud reflections you've put on there. For some reason it looks a bit fluffy in places.
Hope you don't take this the wrong way because I'm nit-picking! I think you have the potential to do even greater work so I just wanted to push you a bit!