This is probably the format you will want to use, it looks like a CD & DVD; The Blueray comes in a sealed cartridge to protect them like old school CD burners & readers used to use. That means computers / in dash won't be able to have the slot feeders with Blueray. There are no HD movies yet so who cares? I guess this format could be used to make perfect copies from a DVD of any size. I don't know what format HD DVDs will be in but if it was mpg4 36GB is plenty...18GB is probably plenty too, and we can keep the form factor we have used for years, unlike a switch to BlueRay In the past Porn would help make or break a format, but not this time as porn in hidef is NASTY.