I think a little higher angle on the first one would have been more flattering. also on the first one, I would have either gotten ALL of the car in the frame, or shot more straight on and cropped it tighter. there's too much foreground in the first, which is just asphalt.
the colors in the second one seem a little washed out. not bad, just a little. I think there's just too much going on in this picture for being an engagement shot. its very hard to focus on the couple. there's the girl with the sign, the car, the building, and the big white line leading to everything. it almost seems like its more of a car shot that people just happened to get caught in.