I was driving on the highway I saw multiple people flash their high beams at me. I pull over right away as soon as it was safe and I saw both my tail lights were out. I was LUCKY - i kept a packet of the replacement bulbs in my glove compartment. I went to replace one of the bulbs, it was out. The second bulb, as soon as I jiggled it - the light went back on. That was kind of weird. Question: Is there some sort of circuit between the bulbs? Also, thanks to everyone on this forum who taught me to do basic maintenance like this on the prius. I'm planning to put the Sylvania LED lights there.