In recent years, more and more people dream of experiencing various IP-based multimedia application services when they are driving through their car. However, those multimedia devices in the car may use different communication protocols such as X.10, Havi, Jini, UPnP and SIP. In order to provide a variety of IP-based multimedia services to those users in the car, the authors mainly investigate the issue of interworking between IP Multimedia Subsystem (IMS) and telematics of the vehicular industry. A service-integrated platform, Open Service Gateway Initiative Service Platform (OSGi SP), has been proposed to act as a Residential Gateway (RGW) and to administer the communication between the vehicular environment and Internet. Besides, a Home IMS Gateway (HIGA), which can be implemented on a NGN RGW, has been developed by Home Gateway Initiative (HGI) since 2005 to collect the relevant information of in-car users, devices and services and to manage the IMS sessions for the in-car devices that do not support IMS functions. With these techniques, the users can enjoy their digital life by interacting with the home/vehicular network from anywhere.