I like it mate, doing cars as your subject is always a risky one when trying with ambient light, mainly because of the harsh light the sun gives and therefore harsh shadows. The harsh light can definitely be seen in shot one, with the windscreen being blown out and the hard shadows under the car in the others, your subject is pretty damn rad but so if I was you I'd line him up for another shoot a little later on when you have some kit to help you make those snaps into shots.
Here's some stuff off the top of my head, feel free to take it or leave it.
So, my tips would be:
#1, shoot early morning or late afternoon, this will mean the sun isn't direct and your shadows will be greatly softened as will the spread of light however so a tripod will probably be needed.
#2, If you use Auto again, I
WILL stab you, it's ruining your shots. (Example from shot #5):
Camera Make: Canon
Camera Model: Canon EOS 350D DIGITAL
Image Date: 2009:07:19 13:17:04
Flash Used: No
Focal Length: 28.0mm
CCD Width: 6.58mm
Exposure Time: 0.0063 s (1/160)
Aperture: f/10.0
ISO equiv: 100
White Balance: Auto
Metering Mode: Matrix
Exposure: program (Auto)To make sense of that, your camera is selecting your shutter speed & aperture & probably ISO.. This isn't hard shit to figure out. Use the focal length vs shutter speed rule and dial down your aperture and use the ISO to compensate. FOR EXAMPLE-(hold on to your undies) Shot 5 could've been shot as per your EXIF OR you could've run something vaguely like this: ISO: 100; SS 1/300th; AP f/4 (or maybe 5). Now this is me just guesstimating and you just learn from shooting in manual mode. What would this have achieved Nick? Well Nick, it would've meant that your shot could have been sharper due to a faster shutter speed (but not really since you were already at 160th) BUT it would've meant you didnt have to see everything in the shot, subject separation is decent in this shot purely from the subject and it's surroundings but the car doesn't really POP on it's own, everything's so damn BRIGHT that it just chills a little, like it's half getting it's head up but that's it. Get me? like check out Brashers' latest shots and just try and read the shot - not drool over how freakin' cool they are, the subject separation is achieved mostly in 3 different ways, depth of field; vignetting (car bright and shiny vs dark background via strobing) and panning (which is practically #1).
#3, Borrow a wide angle lens: Reasoning is, in your 'in car' shot and your engine bay shot, you have to stand back pretty far because you have a 17-85 AND a 1.6x crop body, this means your 17mm wide end is really closer to 30mm. On a FF like a 5D etc.. it'd be plenty wide enough but on the lower end digitals it's not really, unless you know how to play it, after all Juiced uses a 17-85 as well and plays on it's barrel distortion which, when used right gives a slight fish-eye effect (READ: SLIGHT!!) so the idea is, get wide, get low and get right in there rather than up and on-top, it'll really make your shots seem wider, especially when you do the cliche'd low, flank shot with the headlight/indicator closest to the lens and make sure your aperture is set to get all the car in focus but that's it.
#4 go with your hunch and get a secondhand flash and let it help you out at just-before-sunset, but by all means get a new one if you can but if I was you, I'd rather get TWO s/hand flashes & ebay RF triggers than one new one, then you'll need stands & adapters etc...
As always, feel free to ignore but that's just some stuff that's pretty generic and most people would tell you if they had the time/effort, but it's the weekend so today I do

.