Buildings would require that at the short end of the zoom be the equivalent of 28mm or shorter.
Depending upon how far away from the vehicles, that same wide angle setting might be important as well.

A camera that uses the industry standard SD memory card and that has a view finder as well as a LCD of over 2.5 inches will be helpful when shooting in lower light without a flash.

Here is a link where you can plug in the features of the camera you and your staff thinks it needs.

http://www.dpreview.com/reviews/compare_post.asp

Go with a subcompact digital camera with 7 megapixels, 2.5" LCD [238,000 pixels] and a regular viewfinder. Comes with a rechargeable lithium battery [which produces around 120 pictures via the LCD or 240 pictures via the viewfinder] and charger. Extra third-party lithium batteries sell for around $7.00. Stores 665 ulta-fine images on a 2-meg SD memory card and sells for $150.00 [without CA tax] thru Wednesday, December 12 at samys.com. It's the Canon PowerShot SD1000 and they are selling very fast.

Good luck!