Used my portable Garmin Nuvi 265W last Wednesday to get from my house to an address in Rockville, MD (for work). It was fine the whole way there (about 3 hours), and I even used the bluetooth feature to take a phone call from work while driving. After we were finished, I got in my car and tried to switch the Nuvi on, but it wouldn't power up (despite having been plugged in for the entire journey). Since I've only had it since Christmas, it was still under warranty and Garmin offered to replace it for free (I had to pay return shipping - $5). They were unable to explain why it failed to start up. All I know is that this was the ONLY time I'd ever left the Nuvi mounted on the windshield after leaving the vehicle. I'm wondering if the direct sunlight caused it to fail. It wasn't melted or anything, but I just can't figure out what happened. Lesson: always stash your GPS in your glove box or center console when leaving your car.