A in-line six-cylinder - also for the commercial vehicles - is at Volvo in the PV 651 since 1929. With the PV 652 comes the hydraulically actuated brake. The PV 36 in turn was the first car of the company with a more streamlined body. It is believed that it was derived from the Chrysler Airflow. But it is by no means a self-supporting body, but all rest on a stable and heavy frame. So the car is neither light nor particularly spacious, what it makes hard to sell with its innovative exterior. Particularly positive is felt the comfort of this car.

Out of the problems with the sales of the PV 36 results the low-priced models PV 51 and 52. The price is still not comparable to the competitors of the class, but now the company has the reputation to build good quality cars. Overall, the body line makes the vehicle slightly smaller, but by the savings, e.g. by reintroduction of the rigid front axle, the weight is reduced by more than 100 kg. Thus, the PV 51 means the return to an affordable car with considerable curtailments, while the PV 52 has more to offer here again.

After the PV 51 has gained more or less, comes the PV 52 with again more comfort than only a windshield wiper and a sun visor. It is available as standard heating with glass plate defroster, armrests and folding rear seats etc. A year later there is a special version, where also the colour design is adjusted inside and outside the modern car body. There are other versions to follow, that would really be called 653 up to 656, because the first digit is reserved at this time for the number of cylinders and the second for the seats. Only then follows the version number.