Kev,
Nice set of pics of a sport I've never actually watched.
I'm no expert here, but I think you've made a good effort at catching the 'non action' side of motorsport (as you point out, Diego is tops at this).
Taking the pics in order;
#1 - Great action shot but a little under exposed resulting in you losing some of the background detail. I don't know if you shot in RAW, but you could try to recover some of the background detail. I had a go with your jpeg and used lightness, plus a curve. Some of the background detail is back in this shot, plus its brought out the bits of flying mud etc which adds to the action, but I'm sure you could do better.
#2 - great shot. I like it. I wouldn't change a thing
#3 - another nice shot, but perhaps under exposed again a fraction:shrug:
I have attempted to bring out a bit more detail, but don't know if its better or not :shrug:
#4 - funny - I like it.
# 5 and 6 don't really work for me, unfortunately.
# 7 and 8 I like. Perhaps a little more post processing (levels and curve in CS2 maybe :shrug: ) might make them 'pop' a bit more?
#9 and 10 don't do much for me again.
In all though a good set. I've had a few goes at getting the 'behind-the-scenes' type shots and its not easy, so well done Kev.
Rich