I'm planning to create a carputer system, and part of this would include an Arduino for remotely turning on the computer/car via SMS.
Another feature I would like to include is internet on the go, hence I will be using a USB 3G modem with the carputer. In an ideal world, I would be able to connect the Arduino to the serial lines of such a modem and listen in for any text messages, and also be able to surf the net using the USB connection to the computer, but having searched around, the only options I seem to have are:
1) Using a 3G modem for the computer as well as a separate GSM module for the Arduino (therefore requiring two numbers/modules/SIMs, not ideal).
2) Using a basic GSM/GPRS modem with a USB-Serial converter, and tapping into the serial lines with the Arduino while the computer isn't using them (not ideal due to GPRS speeds).
Does anyone know of a 3G modem that has both a USB and serial interface, or does such a product not exist?