Cheers for the replies!
OK, I will let you all know the story.
I'm going to France in a month's time for the Le Mans Classic - its classic cars racing on the Le Mans circuit with half hour races back-to-back for 24 hours. Im going down in a Morgan - hence next to no luggage space. This means I cant take my 120-300 2.8
I would really only be able to take one or two lenses. I also hate changing lenses in the field (fiddly, dust on sensor etc etc), so I was after one of the new 18-200 VR nikkors. However, these are like hen's teeth unless you are willing to pay around £600+. Now, I'm not willing to pay such an amount for such a lens.
Therefore it looks like I would have to take my 18-70 and Sigma 70-300 APO, which I'm not all that happy about.
Now, the car owners clubs from all over Europe are going to be there. There will be rows and rows of awesome cars to photograph - such as a line of dozens or so 911s from just one generation (e.g 996). Therefore I thought a wider lens would be fun for capturing such shots. I could also use it for landscapes etc too. I could take a 12-24 for close ups, and my 70-300 for the track stuff. And thats where we came in. Sorry for the long post!