Midday isn't good for much that isn't in a studio or somewhere that doesn't reflect the harsh lighting.
Have a look at your first pic; along the side of the car there is a messy looking reflection from the side mirror halfway along the car. Then while the bonnet is blown out you've lost shadow detail for the rear wheel.
Third is best to me; but it feels that the rear of the car is disappearing into the shadow at the rear there. Same issue with blown highlights too. P&S = 8 bit jpeg - the extra latitude of raw would be really useful here. HDR was suggested and can be used well but you may be able to get enough in one exposure if you could shoot raw.
The fourth has the most compositional issues if you ask me (I'd like a bit more symmetry in the first two though...). It feels very cramped; the antenna of the far car is cut; it looks bad for the wheel and side view mirror of the close car too. If you were to try this sort of shot again I'd look at positioning the far car more towards camera left and have a 3:2 crop instead of closer to 1:1 so you can see onto the door of the rear car.
Any lit carparks open at night near you? You could get some interesting lighting there potentially. If you're aim is car ad style lighting; well, I'm lead to believe that a lot of that is now done cg to get the lighting for it.