I strongly recommend the EF-S 17-55 f2.8 USM IS for crop. The 15-85 may be a good alternative if you don't need the speed. Granted, for trucks alone, you may want to stop things down a bit for greater depth of field so the 2.8 may not seem to be a big benefit. But, I found it to be a life saver at events, for candids, for sports, and for more creative control with a smaller DOF.
This lens has two quirks.
1. The zoom resistance isn't even. It feels a little tighter around 24mm than the rest of the range. But, for me, this is most noticeable when I'm playing with the lens and wondering if it's an issue. Frankly, it isn't. I forget all about it when I'm shooting.
2. There are vents in the front of the lens that can draw in dust when you zoom. Actually, many lenses have this. The easy fix is a protective filter, which I would recommend anyway. (I use the Hoya HD clear.)
This lens has "L" quality glass that is tack sharp even wide open. I've also been very impressed with its focusing speed when matched with a 7D for indoor sports. Some may criticize the build quality because it doesn't compare to an "L" lens (like the 24-105), but I don't see this issue. It's one of those things that you don't notice unless you're comparing it directly against an "L" lens.