I have inserted the sound system into the dvd's and did come across some difficulties because I had short circuited the Kill Bill one so had to rush to Clintons to get some more cards.. which were double the price I payed on Ebay! Anyway I wanted to also colour the white tabs that tiggered the device to activate black, so used a pernament marker. Little did I know that this somehow affected the tigger and it wouldn't activate it. It took me a while to figure that out and then when I did I managed to find some tabs that I had thrown away because I thought it was no use. After changing it over I used black tape to stick it down and carefully placed everything in line. Another problem that came was that when I opened up the dvd it would speak with a chance of 50/50... this was because the tab wasnt fully or freely being pushed into place for it to be activated and ready when opened. So I had glued on a little notch which will push the tab back into place making the sound system to be activated everytime when opened so I wouldn't worry about it. I'm not sure whether to hide the device with a blank card, but I quite like allowing the viewer to see the device system and how it was constructed. Something to think about I guess