VXOC Astra-J/GTC

Hi
Just bought a GTC with navi 900 installed but the navigation software is pants. Used it on the way from the dealers to get home, 90% on motorway, but it kept directing me off the motorway down roads that were not on my route.

Is it possible to simply have a 3rd party nav software, such as tomtom, on sd card and insert in the car or is this not possible?

Thanks

no not that i know of
you can set it to fastest or most direct route settings

I can't see it being possible at all. If you could find out the base system you maybe to look into the possibility of using a different system but again I very much doubt it.