...I'll give my thoughts (hoping not to pi$$ off too many)
...for nearly 15 years I helped organize photo shoots for different magazines and freelance photographers which is how I got so many of my cars in magazines and books thru the years....I watched them all intently and learned what I could...
...several simple rules the magazines/photographers insisted on
* NEVER, NEVER, NEVER shoot a car on grass.....they were made to run on the streets...I had a photographer here from England once and he said quite distinctly, "grass is for taking a picture of your pet, not your automobile...."
* ALWAYS have the sun to your back and the shadows on the side of the car you DON'T see...always get better results on overcast days than in the bright sun
* 45 degree angle shots with the front tire turned to show the wheel are the favorites of publishers.....shows alot of the car and you can get a bigger/closer shot of the car with an angle than a straight side shot...it also looks like an 'action' shot rather than just parked...
* background...we shot many of the cars at a local airport so there was nothing but pavement, sky and the CAR...it was a car magazine....they didn't want poles/trees/mailboxes etc etc sticking out of the fender/roof of the car being photographed...the Brittish photographer was more bent towards artistic shots and was far more creative than the guys shooting 30 cars per day...we experimented with colors and backgrounds far more than with the other magazines...I like to use backgrounds similar to the one in the pix I have entered in the contest....the corn stops the eye from roaming all over the photo looking at everything EXCEPT the car...contrasting color helps too
* magazines rarely print black cars (waste of their color pages).....
* contrasting colors enhance your photo....light color cars need darker backdrops...dark cars need lighter backdrops...still hard to beat an airport....don't shoot green/yellow cars with any or much foilage(not enough color contrast)....don't shoot black cars with green in the picture at all....green and black suck when together in a photo
* avoid distractions in your photo....distant buildings/poles/wires/lines on the pavement/trash....we even picked the gravels out of the treads everytime the car tires were rotated.....look the picture over closely before you snap the shot....
many many more things to think about but I figured I have bored everyone sh!tless by now anyway....
...so it's easy to get good results.......just take your time and look things over before you press the button
pix 1....yelo car....I like to play with backgrounds sometimes
pix 2...red car......it's difficult to go wrong with a clean simple background....I get many of my favorite shots on country roads....