SilverCloud Real-Time GPS Tracking System has a good rating for the ability to track vehicles, including fleets. The system provides online maps, real time information and vehicle numbering abilities.
A good vehicle tracking system would be a GPS. It's easy to get your hands on, sold in any electronics store, and is affordable. It's also good enough to suit the job.
There are many options for bug tracking software. Some of the more popular include Bugzilla, Trac, OTRS, The Bug Genie, Bontq, Fast BugTrack and AceProject.