When I stepped off the S-Bahn at the Neckarpark station in Stuttgart, on my way to the Mercedes-Benz Museum, I ran into a gaggle of Idaho high-school students who nicely summed up the two car museums they had just visited.
"Mercedes has more details and has more history," one of them told me. Porsche, he said, was more about the brand and its racing heritage.
There you have it. My work is done. Stuttgart is home to these two luxury brands and as a car guy and motoring journalist, I have always wanted to make the pilgrimage there.
Germany does not have the sort of geographic centre for its car industry that the United States has in Detroit. But since the companies' founders got their 19th-century starts in Stuttgart, it comes closest.
I had heard that the Mercedes- Benz Museum, like the Henry Ford Museum of American Innovation in Dearborn, Michigan, offered an exhaustive history of transportation.
I also knew that Stuttgart was a must-see for Porschephiles.
I got my excuse to visit when my daughter Marian moved to Dusseldorf, an easy train ride away.
My first stop was Mercedes, which presents a captivating walk through the birth of the car with the kind of historical sheet-metal eye candy that will wow a car fanatic.
It is a tale the company is allowed to own because a founder, Karl Benz, is credited with making the first car and its other founder, Gottlieb Daimler, was not far behind.
But before I even entered the museum, I was stunned by the building.
Opened in 2006, it is a double-helix design by Dutch architects UNStudio and sits like a round jewel in Mercedes Street.
Though Henry Ford made the car popular with his affordable Model T in the early 20th century, it was Benz, an engineer and inventor, who got things started in 1885, when he installed the almost-1- horsepower internal combustion engine he invented in a three- wheel buggy.
The building provides a floor-by- floor circular walk through Mercedes history over its nine floors and 177,000 sq ft of exhibition space, with the timeline starting on the top floor.
There, I found a reproduction of that first car, with the real Daimler car next to it.
Actually, a horse, thankfully another reproduction, greeted me as I began my tour at the start of the automobile age, when 1 horsepower meant what it advertised.
To my jaded 21st-century eyes, those cars looked more like contraptions than useful transportation, but the engines were evidence of the true genius of these men.
As the technology improved, internal combustion engines got the world moving and ended up in buses, trucks, boats, airships and tractors, some of which are on display here.
A descendant of those engines is sitting in your driveway. Within a few years, cars started to look like cars instead of horse-drawn carriages, for example, the museum's 1902 40 HP, the oldest-existing Mercedes-branded car.
Still, the industry used carriage types to describe its models, like phaeton (a light, open carriage), shooting brake (a carriage meant for gamekeepers and sportsmen) and cabriolet (a light, hooded carriage drawn by one horse). Even dashboard is a leftover carriage term - it was the board that insulated the driver from dirt from the road.
The museum can seem overwhelming because there is so much of that history to take in and so many beautiful cars to sigh over, like the 1955 300SL Coupe, known as the Gullwing.
You will learn that Mercedes was the name of an important customer's daughter, Mercedes Jellinek (interesting that her father, Emil, eventually changed his last name to Jellinek-Mercedes), and that the company's logo, the three-pointed star, symbolises earth, water and air.
I travelled to the museum by train, but left with a strong urge to drive, something from the AMG performance division preferably, but alas, there was no opportunity.
I went to the dealership on the bottom floor, but was told test drives must be scheduled about a week in advance.
There is no such problem at the Porsche Museum, about 11km away from Mercedes. The Porsche building, which sits on three V-shape columns, is striking and seems to float above the ground. It was designed by Delugan Meissl Associated Architects of Vienna and opened in 2009.
Representatives in the lobby will let you drive, say, a 911 for about US$165 (S$222) an hour and up to about 97km, but be aware you have to leave a US$3,000 deposit.
No matter - see the museum first. It is more straightforward than Mercedes', with everything on one floor and a loft. It contains more than 60,000 sq ft of exhibition space and the displays are spread out.
You can follow the development of Porsche's models, from the design ultimately used for the Volkswagen Beetle, first created by Ferdinand Porsche, the company founder, to the car that defines the company, the 911.
You can see how the sleek Type 64 race car from the late 1930s led to the beloved Porsche 356 and then to the 911. And for fun, there is an area where you can press buttons to hear the engines of several cars, like the Panamera GTS.
Also impressive is the case that displays dozens of trophies from the company's 30,000 motorsport wins.
If you love the brand, especially its racing history, you will love this museum.