Germany has many diplomatic relations to a lot of European countries. If you have any problems with your car while being in foreign countries prevention in form of an abroad car insurance is worth it's weight in gold.
If you want to drive by car abroad then you always need to have a car insurance when passing the border.
Without this insurance it is possible that your car will be confiscated in case of an accident. If you cause an accident or injuries to people you should immediately notify your insurance company and ask them for help.
It is also recommended that you become very familiar with the traffic regulations in the foreign land before starting a journey.
In many EU countries there are special conditions that you need to take care of while operating a vehicle. These include the need of safety vests in your car, drive with light even in the daytime and a maximum speed of 100km per hour on motorways.
Furthermore it is always possible that there are specific traffic signs that you don't know from your home country. It is best practice to acquire a road map with the usual signs of the host country.