Migration and drivers or kext programs?
If it was easy to find all of the system items associated with an application, Migration Assistant would've done it for you; generally, if it can't figure it out, the easiest solution is to reinstall the software that didn't come over cleanly.

There is an alternative, however: clone the entire volume with something like Carbon Copy Cloner.  This'll get all of the add-on software fine (except things like hardware-tied license keys and such), but may run into compatibility problems with the new computer.  For example, if you clone from an older system to a new one that requires a special build of the latest OS version (with new drivers &amp; such for the new hardware config), you may have to reinstall the OS (from the disc that came with the new computer) to get that to work.  Pick your poison...