Hi there

We are 3 friends (around 30 years old), who want to travel from Hamburg to Barcelona by car next week (April).

We will have 3 days – which I know is very short!

We will leave Tuesday morning and want to arrive on Thursday evening. Everything inbetween is open. We plan to make the first part of the journey very fast, so we won't spend much time in Germany. We are also open to drive at night and long hours.

Does anyone has suggestions for nice spots to stop at on our way?

We are looking for scenic views and must-sees.

Every suggestion would be appreciated. Thanks!!

Best,
Allegra

Before you consider where you might stop (if you even have time), it would be useful to know if you're driving your own car, or renting. If the latter, have you checked on how much extra cost is involved in renting in one country and dropping it off in another? It can be a small fortune.

The fastest route is towards Karlsruhe and cross to France near Basel and head down from there. Takes about 16 hours driving assuming no traffic, but it is motorway all the way and boring. It isn't cheap in fuel either - about €360)
If you are in your own car then head for France on the autobahn then stop somewhere around Strasbourg, you can then potter somewhat from there to Barcelona over the next couple of days.
Unless you have a vignet for Switzerland stay out of Switzerland. Likewise German cities unless you have an Umweltplakette.

If it is a hire car, and a one way rental consider flying. By the time you have paid rental, one way charge, fuel and hotels it will be a seriously expensive dash.

Did you look up google maps? It calculates just over 18 hours for your trip. Now, everyone who has tested the times indicated by GM will be inclined to add approx. 30%, in view of the almost endless list of roadworks shown by GM on your route even more. In the end you probably will have half a day for "nice spots" and less driving fun than you might have expected.

Trusting that you have calculated and are fine with the costs mentioned earlier, including the road tolls in France and Spain, I suggest driving all the way to Dijon on Day One. You’ll get there by dinner time if you leave pronto in the morning. Either via the Frankfurt/Freiburg route, or via Köln/Luxemburg.

Now you can play - Avignon, Nîmes, a drive through the Camargue (pink flamingos, white wild horses...), lunch at Le Grau du Roi overlooking the harbor, spending the night in Carcassonne (no need to fear for your lives, the Dominican monks are behaving themselves these days...), etc.