The first page of the thread covers the subject, then a fight broke out followed by a 'how to post' lecture then, finally, back to photography.
Your opening post covers the most common mistakes in photography, not just photographing cars, along with simple solutions. Personally, I'd move composition to the top of the list because if a person can't decide what the photograph is supposed to be about, it's going to be a snapshot that stays in a shoebox. The following is nothing more than re-stating what your first post said, in a little different order and form, 'way back at the start of this thread.
Even with a digital camera, you should stop and look at what's in the viewfinder before clicking that shutter. What's it about? What's occupying most of the frame? What's distracting? Does the background interfere?
Crop it! You shoot a little extra in the frame just to make sure you get everything you were after, but before you print it or publish it, you trim the fat off. If the photo is about your car, your house shouldn't occupy half the image. Measure it. Most of the time you will find that around 2/3 of your image has nothing to do with what you want to show. Would you enter a drag race while towing two taxis? Same thing.
"You can't really tell because it's so dark, but...". If you have to explain it, it's a failed shot; the only image you're presenting is the one you remember, not the one you meant to have in the photograph. Cameras capture light, not brain waves, auras or memories.
No amount of special effects, filters or weird angles and rotations of the camera will fix a bad photo. They can ruin a good one, though. Photograph, don't decorate.