Americans driving in germany

About as easy as driving between states in the US, provided you know the Swiss and German driving laws. If this is a rental car, be aware of the very substantial drop off fee for dropping in a different country. You will need an IDP for each driver.

That's a fairly easy drive, but it's faster by train. Still, if you drive you really need to know how to drive in Germany. Traffic moves much faster than you will be used to, the roads are mostly just 2 lanes either direction, and the speed limits and passing rules are strictly enforced. The DOD studies show that the first 30 days in country are the most dangerous for American drivers.

And if you choose to cut through Switzerland, you will need a Swiss vignette for the car when entering Switzerland, costing 40 CHF. If you enter Basel from Germany, you can probably avoid this.

Driving in Germany is relatively easy as drivers tend to stick to the rules of the road. Speed limits are pretty strictly enforced often with the use of speed cameras. Friends from Europe have commented that in the US, the speed limit seems to be the minimum speed for most drivers while in Europe, the speed limit is pretty much the speed limit. And I have noted a definite increase in enforcement in recent years - much more so than in my visits 10 or 20 years ago.

Speed cameras in Germany are often placed in locations where the speed limit changes and drivers who don't adjust are likely to see the flash of the camera going off. I know this from personal experience having picked up three tickets on my first trip to Germany post Covid. This can happen on the Autobahn as well as on secondary roads. You may not realize you have been ticketed until a letter shows up in your mail months later. And, unless you have friends or relatives in Germany who will help with paying the ticket, it is a major pain to pay as all the communication will be in German and credit cards are not accepted. I was lucky enough to have someone in Germany who paid the tickets for me (which had to be paid to separate jurisdictions).
Oddly enough, the fines are light - one Autobahn violation and two violations on secondary roads only totaled about 25 Euros but the cost of paying them would have been more than double that if I had had to arrange money transfers for payment.

I suppose someone could just ignore the fines but as I travel to Germany and rent cars on every trip, that was not an option for me.

I've driven in Germany on two separate trips and have never had any problems. It's very easy; just plot out your route ahead of time for convenience, and follow the speed limits and other directives (i.e., no parking, etc.).

Road signage is different. Signs will mark the town/city you are heading in the direction of, rather than east/west/north/south we are used to in the US. Also, speed limits are enforced at the posted sign - no slowing down zone.

I would also get the International drivers permit. Not sure if it is required but to me is worth it for ease of mind.

and the town name with a yellow background means town speed - from that sign, not where you come off the gas and slow down. That is no more than 50 kph unless signed lower. In tiny hamlets the sign will have a green background, so no 50 required. But it may be posted 60 or 70.

you need to do some studying - it is quite different signage. The cars are similar.

if you have a Swiss rental it won't have the German Umweltplakette which allows driving into Munich. Munich requires it for the environmental zone, like other German cities and areas.

Even if you have a car with the Umweltplakette don't try driving in Munich unless you like headaches and very difficult driving. And certainly don't go near the Hauptbahnhof - the whole area is a construction zone while the station is being rebuilt.