TomTom has teamed up with Toyota to develop "the world's first embedded portable navigation device", which will come as an optional extra for Toyota Yaris car models.

The new plug-in GPS system comes as a part of the Toyota Yaris' built-in radio system, as an add-on navigation device. You'll be able to slot the satnav device in securely when you're in the car, but remove it and take it with you when you're not. Power will be drawn from the integrated car socket, so you won't even have to charge the unit up.

Spoken instructions and hands-free calls will be routed through your car's stereo system, and you'll receive software and map updates as you would with all other TomTom products. You also have access to TomTom Home and all its content and services.

"Bringing our extensive navigation experience and insight into the automotive industry is an integral part of our long term business strategy. The embedded solution offers an affordable and improved user experience to customers and we are delighted to launch this industry first with leading automotive manufacturer Toyota," said TomTom CEO, Harold Goddijn.

Toyota's TomTom deal could spell the beginning of the end for expensive, non-portable satnav systems that are often factory fitted by car makers. By offering a portable satnav dock, Toyota is actually offering the best of both worlds.