Hello, i have a question about my rx300. I was sitting in my car last night with the key in the position between accessory and start, the white dash lights were on, the navigation screen was on, I had the radio on, I had the fan blowing etc. Everything but the engine was on. After about 20 minutes the navigation screen went darker, then it went out all together. I turned the key to the off position then turned it on, and the navigation screen was still off. I tried this again and it came back on. My battery dead? The car still started this morning. Thanks for your help the car is 4 years old.