Hello, Andreas, I am experienced in the development of devices based on the GPS, GPRS, Bluetooth technologies. Also, I have experience in the development of car navigation terminals (see in my portfolio Automobile navigation terminal "NT-110G"). I can develop this device for you, taking into account all your requirements. Also I can prototype the device. I I'll make this work qualitatively, because I'm interested in long-term cooperation. Most of devices in my portfolio are put into mass-production. For details, see PM. Best regards, Eugene.