Stop blaming your car and pay attention. (it is so simple and it makes so much sense )
You probably heard of inversion tables or a method called “traction” (Traction is like being put on a table and pulled apart from head and feet) This two methods work because there is a very slight separation of your vertebrae. That small rearrangement of the vertebrae produces some relief. This achieves back pain relief but it is only temporary because a short time later your body goes back to normal. –It works but it is not very useful–
Now comes the interesting part: Your body can do exactly the same thing by itself. Continuously and at any time! An inversion table uses gravity to pull the spine apart. Your body on the other hand can do the same because it can build pressure in your abdomen by using core muscles. You have something like hydraulic jack inside the body and you can use it to separate your spine anytime and give you lower back pain relief. You can read the explanation here. Getting the book is better than getting new seats. You will thank me later.