I know there's a raft-load of GPS questions here already but I just want to ask a couple. 1. Can I use a car-type GPS unit on my bike if I put it in my tank bag and use bluetooth to relay the instructions? The reason for this is that, if you could, the unit could do double duty, on the bike and in the car. 2. What are the technical issues associated with using a GPS with bluetooth? Is it easy enough to do or is it such a hassle that it isn't really worth it? Any help appreciated.