Yes, the Baden Baden to Freudenstadt route via the Schwarzwald Hochstrasse is one of the finest routes in the area.
When you get to Freudenstadt, check out the Stadt Platz (city sqaure) and stroll around and look at all of the places manufacturing and selling Cuckoo Clocks.
Also in the area on the Neckar river is Neckarsulm and it is there that I first discovered the Deutches Zwieradmuseum (German Two Wheel Museum) you can see the worlds first patented push bike and it goes on up to some of the most stupendous motorcycles I've ever seen. Small entry fee.
It is located in a Schloss (Castle) that as far as I can work out is where the NSU (NeckarSUlm) factory is/was located. This was the first place to manufacture and/or develop motorcycles in Germany.
Neckarsulm is very near Heilbron and from Heidelberg to Heilbron is a tourist route along the Neckar river, which takes you past the museum.
I myself visited this place in a motorcar with my German girlfriend (now my wife) and even though she was only sort of interested in motorcycles, she warmed rapidly to the museum as it does take you along a chronological path from genuine push bikes (no chains etc.) through to one of only about 40 to 42 Kompressor BMW Rennsport machines ever made. The museum has a genuine original and it's worth seeing.
Lots and lots of English bikes as well.
Stretching the friendship bit about the Black forest area. One could extend the trip to Stuttgart, capitol of Baden-Würtemberg there in the now suburb of Stuttgart is Cannstatt which is where the Daimler-Benz museum is. This is probably the best museum in the automotive world in some aspects. Firstly it has the worlds first patented Automobile by Carl Benz and alongside that is the worlds first patented horseless carriage, patented by Gottlieb Daimler. These are the originals and no where else can you see this real distinction as easily as there. Last time I was there it was free entrance.
There is a chronological order as things Teutonic are.
You will see Aero, Zeppelin, Boat, railcar and of course automotive engines and machines. There are some of the most fabulous motor vehicles ever manufactured, in that museum.
Including a 1939 43 litre world land speed record car, which never ran in anger. The Autobahn between Stuttgart and Munich was booked for an attempt at the land speed record on the mornings of September the 1st. 2nd. and 3rd. of 1939. Unfortunately, the government of the day had a party in Poland on the 1st. so it was shelved, so to speak.
Mick.