There are lots of people using IDE-USB2 adapters. Some people also use firewire which in my opinion is better as it is designed for streaming and has a better sustained transfer rate hover USB2 should be ok and is more useful for other peripherals.
The normal USB range is 5m without a powered hub so you should be ok going from your boot to your dash. One that comes to mind is Gorks Bimmer with a slot load lappy DVD in his headliner connected by firewire.
Oh try looking in one of the general hardware sections you will find some discussion about this there as this section is for development of stuff so if you were doing a search only int his section would wouldn't get anything.