Please help, pulling my hair out ! Mk III upgrade

[dmg]

Hi, This is my first post although I have been reading this forum for the last 3 days whilst I have been trying to upgrade my MK III unit O/S. current level is 3.1/32 and its in a range rover, all works well but I want to upgarde to get postcode search. I am in the UK (Essex). I have burnt about 20 disks ranging from V22 to the latest V31. I have made sure the images are in mode 2 format and burned the disks in mode 2. I have tried 3 types of disks and burnt at no faster than 4 speed. None of the disks have worked and i think it may have something to do with the RR mk III unit? Any help / advice would be gratfully recieved, an upgrade to MK IV would be ideal but I havent the cash at the moment. This is driving me nuts, please help before I pull whats left of my hair out.