Where to go in Switzerland for a day?

Joseph, where will you be taking this day trip from? Munich?
"My 17 year old son and I will be going to Munich for a week." - but where will you be when your wife and daughter are with you?
Switzerland is too far from Munich for a day trip. I suggest you take a day trip by train to Salzburg. That would add Austria to your list.
Lots of other places day trip distance from Munich.

"In Munich we will have a car." - you are aware that you cannot drive around central Munich, neither is there anywhere to park.

We will leave my wife and daughter in Paris. They fly home and we fly to Munich. We were in Munich two years ago and really liked it. We want to visit the old city center as well as the BMW tour. Other than that we are open. My mother-in-law is from Czechoslovakia and therefore we want to at least visit there. I looked at flying to Prague and spending a night there. The thought about Switzerland came up. According to the Google Gods, it is a 3Hr, 9 Min trip. The idea is just to say we were in Switzerland and secure chocolate for the less fortunate at home working

Joseph, according to the lesser gods at https://www.viamichelin.com/ from "München" to Luzern by road is:

Distance: 370 km including 345 km on motorways
Time: 04h04 including 03h18 on motorways
Costs: 77.24 € including Consumption 30.89 €, Road tax 46.35 €

But always add 25% to 50% to times, because the above assumes no stops for any reason. Conclusion: not a day trip.
From Munich/München to Prague/Prag/Praha I would not fly. A train or a DB-operated bus would be quicker and more comfortable.

If you want a fix of Alpine mountains, I suggest Garmisch-Partenkirchen, then train up Zugspitze. And a visit to the totally OTT castle at Neuschwanstein.

Just spend the day in a Munich beer-hall. You can buy chocolate anywhere and lie about where you got it. Marriage 101.

"Just spend the day in a Munich beer-hall. You can buy chocolate anywhere and lie about where you got it. Marriage 101."

I LOVE it!!!!!! Unfortunately, she would know. They ALWAYS know when we are less than forthright, and then we pay. Oh Lord, do we pay.

Chris, I was getting the route from Munchen to Zurich. That is where the 3 Hr 9 Mn came from

For you, Luzern and do Pilatus and Fraekmuentegg.

I would add 1-2 hours for any driving estimate from Munich to Switzerland, because there's two major choke points that can snarl your trip. One is leaving Munich (it should be stressed again, don't take a car into Munich unless you have no other choice!) and the other is the tunnel through Bregenz. Sometimes traffic here is clear, other times it takes an hour to get through the damn tunnel. So, keep that in mind if you decide to make this drive.

If you just want to drive to a nice Alpine location, you can consider the high-altitude Alpine town of Flumserberg in the canton of St. Gallen, which is only about a 30 minute drive into the country from the Austrian border (yes, you have to drive through Austria to get to Switzerland from Munich, which means you'll need to purchase a highway vignette for both countries). Unlike some of the other well-known high altitude towns that people gush over on this website, you can drive up the mountain to the town. However, weather is a constant battle in the Alps. You could leave Munich with sunny and completely cloudless skies, only to find the mountains draped in fog upon your arrival.

And if you really only want to see the Alps... just make the one hour drive south to Garmisch-Partenkirchen.

Tom, that is exactly what I was looking for. Thanks!!