I had left my bluetooth cell phone in my bedroom the other day. It is a Sony-Ericsson T616. When I pulled into the garage, I started shutting down everything, and I heard a beep. I looked at the display and saw the 'bluetooth device found' message. I thought, that's odd, I don't have my cell phone with me. Then it dawned on me, it must be picking up the signal from my phone in the bedroom. There is a utility room between the garage and the bedroom. I didn't try to make a call, but I'm sure it would not have been very good quality. But still that seems pretty impressive to me.
I can control my laptop with my SE T610 from one floor up. OTOH, the T610 loses my headset if I walk more than about 2 metres from the phone. The commonality here is both your Prius and my laptop would have essentially unlimited Bluetooth power and thus the range would be pretty high. The headset OTOH is very low power and thus the range is very low.
