Download the igo8 .txt version of the redlight camera sights, rename it speedcam.txt, then copy it to \My Flash Disk\Miomap\Miomap\POI\Speedcam\ directory, you have to rename the file to speedcam.txt for it to work. Now reboot the mio and see if it works for the 320, it does for the c230.
\My Flash Disk\ is the mio c230 Internal 1GB R/W Flash Disk.