Car production from 1898 to 1921
The bicycle success gave a good connection with Frederich Lutzmann, whom also was a professional locksmith. He had in 1893 bought a Benz Victoria and made some alterations with some of his own inventions and improvements. Opel succeeded to persuade Lutzmann to move his production from Dessau to Rüsselheim,
whom in Opel REGIS developed in 1898 the Opel-Patent-Motorwagen, System Lutzmann. 
The following year 1899 the public could buy the first motorcar by Opel with the System Lutzmann. Eleven cars where sold.
The engine was water cooled with one cylinder and automatic valves. The transmission had two forward gears and one reverse. The top speed was 18-20 Kph and the engine delivered approximately 3,5 HP. The price was 4.000 Mark.
The development of Opel on the automobile market went quite well. The deal between Opel and Lutzmann was that they in common should develop end build new cars, but Lutzmann was more interested in developing existing models. This meant that they had trouble to keep up with the competition on the market, and this meant that Sophie Opel told Lutzmann that the cooperation had to stop.
Three of the brothers went to France to study car production with where further ahead and they made license deals with Renault and Darracq. Specially the work with Darracq went well and in 1902 Opel the small Opel-Darracq with a 1.1 Liter one cylinder engine with 9 HP. Opel where quick at learning the art of constructing automobiles, and they had good experience with marketing from the bicycle adventure, so they had a good start with car production. Even activities in motor sport gave them good publicity.
Their first car that was a pure Opel came in the fall of 1902 – it was the 10/12 PS model witch had a brand new two cylinder engine and already in 1903 they offered a four cylinder engine. As parallel production to the cars they introduced a motorcycle with 2 HP witch was offered in 1902 and had a price of 700 Mark.
Opel also started to produce some farming equipment, lorries and aircraft engines. In 1911 the years production reached 2.551.automobiles in one year.
The same year a major fire destroyed the factory, but already the following year they could open a new factory of 6.000 square meters dedicated to car manufacturing. 3.100 people where employed in the factory and in 1912 the made 3.202 cars! It took six weeks to produce one of the small cars and three months to build one of the bigger cars. The building method became more and more overwhelming the higher the production numbers where together with more and more models. The biggest hinder for accelerating the sales where the high prices on automobiles at that time. Most car manufacturers where interested in building cars for the broader public. Opel Answer to that was in 1909, the 4/8 PS model with became known as the Doctorwagen. This car was not to large and very easy to handle. Now it was possible for lawyers, doctors and vets and so on to visit their customers without the need of a chauffeur.
In 1911 came the new exclusive 6/16 PS model. In the end of 1914 they launched a new model with four seats. That was the model 5/12 PS and 5/14 PS. This model made Opel Germany´s biggest car manufacturer. In 1919 Opel completed their race and test track witch opened in 1920 and ten thousand people came to the inauguration.