there isn't a whole lot different when it comes to automotive photography vs any other kind, there are little things that are different, but most of the subjects of focus, depth of field, lighting, angle, and most others are all going to be the same no matter what subject you're shooting.
if you're shooting the whole car, you want to make sure to choose a good DOF to get the entire car in focus, unless you're going for something specific, say like an emblem close up, or the front end, or something that a shallower DOF would work better on...you know, for artistic purposes. also think about the angle you're taking the shot from, everyone can see a car from the standard standing next to it angle...move around and find what looks good, or accentuates the car's design...
Focus is the same as anything else. composition rules are the same....a big thing that people do with car photography is they cut off little portions of it trying to fill the whole frame, take a step back and look, are the bumpers in the picture? if the hood is open, do you're not cutting the corner of it off or something, right? is the image straight?
lighting is a bit harder and sometimes you have alot less control of it. outdoor shows have shadows, etc, inside shows many times have lower than needed lighting. flashes can create harsh reflections....if you don't have full control over the car's positioning and lighting (like at a show or something) you can try bouncing your flash which can help out alot, or using a diffuser/bouce card....but reflections are one of the hardest things with cars since many of them are like mirrors. get a GOOD circular polarizer, it can help you control the reflections and the transparency of the glass.
make sure you're shooting in RAW if at all possible to get the best quality. watch things like your white balance since most car shows use various lighting sources...
shooting a car that you have full control over the environment isn't overly hard, take your time and get it as perfect as you can in the camera, don't try to rely too much on post processing....shooting things like shows and such is ALOT harder to get great pics, but if can be done. take lots of pics, I like to shoot 2-3 images of every shot in rapid succession, sometimes the first one has a little camera shake or something and the subsequent pics don't, it just gives you more options to chose from. and its not like film days when you'd have developing costs related to each image, choose the ones that you like, and get rid of the others. see what you did right on one shot and what you don't like on another, learn from your mistakes.
I have a small automotive site that I run and I cover some shows here and there, I almost never have a vehicle to shoot as I please, I either have to do it as they're going down the track, or on the showroom floor or something. I'm not perfect at it, but I learn something each time I cover an event. and the pics just keep improving...here are some of my recent event pics that I have done, some are better than others:
Here's a Bugatti Veyron that was at a show, of course they aren't going to let people get close to a car this expensive, so telephoto was my friend here, but I'm a bit disappointed with the lighting, it was outside around 11am so the sun was harsh, and they had a large frame structure around it which was casting shadows, not to mention a bunch of equipment obscuring some of the car...it was HARD to get a good shot of this car, these were the best of the ones I got. and although I could do some post processing to clean up some of the things, I shot over 1200 images at this show, so doing so on everything was just unfeasable. this is MOSTLY what I got out of the camera minus the cropping and image size, etc...
here is one that the outdoor lighting turned out a bit better on, however with shows, the background you usually have very limited control over, so there is usually always people, and sometimes things (like the garbage can in this pic) that you can't control much.
cars in motion are hard, you want to know beforehand if you're going to try and freeze the motion with a fast shutter, or see some motion blur with a slightly slower shutter speed. get used to panning with the vehicle while shooting too. these were all while the cars were in motion and panning with the vehicle. its like shooting sports, set the camera at successive shots, and just hold the shutter release down for however many images you would like, try to get images before, durring and after whatever is happening...these first two images are of a powersliding/burnout trial in a confined space, so there were alot of images I took leading up to these ones that I didn't use...its better to get too many and not use some, than not get what you wanted because you were waiting too long to take the shot.
these ones were cars racing on the salt flats through a 200mm lens, again several photos with these being the best
this one I got of the truck driving by me, I just got lucky that I was at a good angle...I didn't expect this one to turn out, but it looks pretty decent IMO for the circumstances it was taken under. don't be afraid to snap at anything you think you might want to shoot. you might end up with something interesting.
These are some decent point of view shots, I had to almost lay on the ground to get these, I also used a wide angle to accentuate the angles of the front end on both these cars:
same thing with this maseratti, but here's 2 pics at the same angle with and without the flash, you can see how the flash brings out the grill and radiator behind it alot..
without flash:
with flash:
another thing you'll run into with shooting shows, is the models...some are good, some aren't you shoot what you can and take what works, be nice to them. sometimes they'll work with you if you ask them to politely, sometimes that isn't possible...and sometimes they've been standing there for a while and are tired of people just taking pics like they're nothing more than part of the show. if you get a chance to talk to them, say thanks, but most of them don't want to hear a cheezy pickup line...in this one I wish I would have framed better to get that pole from obscuring part of the grill, but there were about 15 other people taking pics so I took what angle I could get. this was inside in a hallway of a huge conference center so lighting was poor at best, I had my flash on but as you can tell its still pretty far from perfect...
well, sorry for the long post, I love automotive photography, and I'm not a pro at it, but these are some things I've learned along the way. hope this helps you out some...