A cheap tripod makes a big difference for sharp photos, especially for lenses that dont have VR, (vibration reduction).
It is difficult suggesting camera settings since they can change day by day, even shooting the same thing.
I am going to assume you have the focus and shutter release still set with as the same button, (factory setting). Be sure to hold the shutter release button down half way to attain focus then push it all the way to actuate the shutter to take the picture. Its important to hold still, any movement while the shutter is actuated will cause blur. I also assume your shooting in the green "auto" mode. You aren't really allowed to adjust any settings in that mode. If you want to continue shooting in that mode, stand about 10-20 feet away from the car, put the red focus box you see in the view finder somewhere in the middle of the car(not on glass) and shoot away at different zooms from different angles, even try to use the pop up flash. Just hold still when your taking the picture.
If your feeling froggy, turn the dial on top of the camera to "A" for aperture priority. This is a setting to adjust the lens "pupil", just like an eye. The larger the pupil(smaller the f number) the better the lens can see in low light. But this also reduces the depth of field, that is the area of the photo that is acceptably sharp. Try turning the thumb wheel to adjust the aperture to something like f8. This tells the camera you want f8 and allows the camera to figure out the shutter speed and ISO for proper exposure. If after a shot is taken and you are not happy with it, make another adjustment and take another shot. See that different apertures provide different results. Further, you can also hold the exposure compensation button down with your right finger and turn the wheel to the right for brighter exposure or to the left for darker exposure. Just dont forget to put the exposure compensation back to neutral when done.
I hope this helps.
Sometimes, its best to get a little info as a starting point and experiment from there. Do not be afraid to take a bunch of shots and delete the ones that suck. Just don't take a bunch of bad shots without making some sort of adjustment, lol!