Nice car

Our family car is a BF XR8... Where did you get the grill and lower grill from? I like.
But back to topic.
1) clean up the Armco, get rid of the graffiti! It also looks a little soft down the drivers side. I would have also chosen more of an angle from the drivers side to ensure you do not see the tread of the tyre on the passenger side.
2) I like, crop it a bit though, take out the chrome strip on the bottom and the number plate recess on the left.
3) good concept, but the white railings are a little too much in the relfection on the car, I'd also like to see all of the car as well, i.e. not have the rims in the ground. Once again the passenger side tyre.
4) car on grass, this is generally a no-no, some work well some don't, with this style of car I want to see the grass manicured and neat. Or long and unruly in a different scene and light. The other thing is the shadow on the passenger side, a reflector or remote flash would have helped a little here (as would different lighting).
Overall I think the time of day is wrong for these shots, you need to be past 16:00 hours to really get the best light, as this is a darker grey it would really show off the later lighting conditions.
PS get the windows tinted
From a PP perspective, have a look at doing some layer based adjustments with masking, this will help to sort the exposure out a bit BUT will be a bit of work.
I think you'll do much better with a later time in the day, also the aperture choice looks good for most. I'd be inclined to widen it up for the second shot though.
Brett