I've serched and reviewed many of the topics on here but can't seem to find the answer. I have an iPhone4 and recently got a new car that has built in USB so i use it to charge my iPhone or listen to music through the USB. The issue I'm having is that not of the alerts for email or text make an audible sounds (yes the silence switch is off) so I'm constantly missing text messages or emails and this drives me nuts. I feel like I constantly need to check to make sure I havent missed something. Phone calls are not an issue because I have Bluetooth which of course rings through the car. Is there a setting Im missing that would make the sounds continue to be heard when plugged into the USB?