As a newbie here and to M5 ownership, I too enjoyed this excellent general guide to good photography, Greg's advice applies to all the shots you take not just your cars of course.
However looking through the galleries it strikes me that some us are so much in love with our cars that we forget to consider the background.
M5's are beautiful we all know.
But who would photograph a beautiful woman around their unadorned garage or driveway if there was a choice.
Perhaps another improvement to many pictures (not Greg's) would be to do justice to your cars, try take your shots somewhere where the background is interesting too.
I know America is beautiful from personal experience, although I won't mention the driving dynamics of rental cars. A bonus is that any trip to a good spot will be another excuse for a drive.
Secondly digital photography has moved on a good deal since the original post.
Any one out there think it is worth a few posts on what is the current state of the art? Keeping in mind of course that this is an M5 forum not a place for photo nuts to run roit.
To be honest the cost of really good photo gear is lower now than ever before and is loose change money compared to the sums some of you have clearly lavished on your cars.
Canon 5D SLR
15mm Fish-eye
20mm Wide angle
50mm Macro
100-400 Zoom
etc. etc. etc.