Car insurance

Your brother in law would get it from the same place he gets the (huge) car.

For recent readers, many of the usual issues were discussed on Floresa's original thread in July.

https://community.ricksteves.com/travel-forum/transportation/renting-a-car-or-train-for-a-family-of-6

Hi. Liability insurance will be provided for free by the rental company. You can buy optional damage and theft insurance from the car rental company, or your credit card likely has damage and theft insurance as a free benefit; get details from your credit card company. Also, see the travel tips section of this website on renting cars in Europe. Enjoy your trip!

You should start by contacting your auto insurance agent to see if your auto(s) primary coverage goes with you to Germany. In many cases, they cover you in most European countries except Italy, Northern Ireland and some Eastern European countries.
When people have a credit card that furnishes coverage, it is often seconday to their home primary coverage. And often coverage purchased from the car rental company is often secondary to your primary insurance policy on your personal car. (Rental ins. in Italy is mandatory but relatively inexpensive.)
When insurance is purchased from rental companies, they pocket the funds as a profit department. Very few rental operations have physical damage and comprehensive insurance.
Like I say, start by checking with your home insurance agent. If not covered, you can go online and read the terms and conditions on your specific credit card online.

You should start by contacting your auto insurance agent to see if your auto(s) primary coverage goes with you to Germany.

I have my doubts as to whether any auto insurance policy in the US extends coverage to Germany (or anywhere else in Europe). The standard policy limits coverage to accidents occurring in the US, Canada, and Puerto Rico.

Have you tried here?

https://www.ricksteves.com/travel-tips/transportation/car-rental-cdw

Your car insurance here in the States will not cover a rental in Europe.

Check out American Express' Premium Car Rental Insurance Program. We've used this every time we rent a car in Europe.

Paul

As per Paul, your insurance in the States will not cover you in Europe. Unless your husband and brother-in-law are named Siegfried and Roy - which I doubt but you never know - you will not cram seven people with luggage into a car.

AutoEurope is your best bet.

Even if you could find a car that would hold 7 people and their luggage, you will do much better with two smaller cars. Not only will they be much easier to maneuver and park, but it will give you much more flexibility, if you want to split up for a day or part of one (say, to see different things in the morning, then meet up after lunch).

Note that credit card insurance excludes some larger vehicles, such as vans over 8 passengers, as in this example from Visa. If you were to reserve a 7-passenger van and get "upgraded" on the car lot to a 9-passenger version, that could be an issue.

Call Andy Bestor from www.gemut.com for advice.

My opinion is to get two cars. A van or any vehicle for 7 will be tough going on a lot of the narrow twisting roads. In larger towns and cities, something that large will be a nightmare.