Smoothing, well I just thought of the fact that those are viewport grabs, meaning you'll have that crappy Max per vertex shading, pretty much any game engine and certainly a render engine will do a better job at the smoothing, so it isn't that big of a deal depending on what you want to do with it. However, you should do something about the body work that folds inside, for example the inside of the wheelarches or bodylines, you could just make a hard edge there with smoothing groups.
And tri's, well of course you don't need all quads, but the flow could do with a bit of improvement here and there. Maybe I'm a bit biased after looking at highpoly wireframes for a month, but I pointed out some obvious spots;
It's things like the mirror surface (=flat, you could do that with far less polygons) or that weird spot above the front wheelarch mostly. The others are about optimization, and you haven't gotten to that yet so I didn't indicate all of those. Also, the green line by the side isn't accurate, look at refpics because there seems to be a bit of a crease which doesn't exist irl. Also the part where the side of the side wheel arch runs through into the door is not accurate.