Poor driving ergonomics can create a lot of muscle pain, especially if you spend a lot of time in the car. Unfortunately, one size does not fit all, or even most, so you will probably need to modify your seat to increase your comfort. Here are some tips on how to do it.
Loughborough University has provided a brochure about driving ergonomics with illustrative photos that help you set up your vehicle to the ideal position for you. Basically, you start with your seat in its lowest, and most rear position, with the least lumbar support, the back rest tilted back and the steering wheel forward. From there, they have you do the following:
Print the brochure and bring with you to your car to make these adjustments.
Notice in the image above that not having enough lumbar support is causing rounding of her back and forward head position. Adding a towel roll corrects this. If your car can cannot adjust to fit you properly, try some of these modifications:
If the seat won't raise high enough, or does not tilt forward to take the pressure of the back of your legs, try a wedge cushion.
So once you have your driving chair set up, you still need to make sure you are sitting in it correctly. As I have mentioned before in proper sitting posture, you should avoid sitting in one position for long periods of time, and should try to make small changes in your position as well as get out of the car to stand periodically, preferably every hour (but who does that?) At least try about every 2 hours to get out for a minute, even if you just pull to the side of the road and stretch for one minute.
To summarize proper sitting posture:
If you are in the market for a new car, I would highly recommend that you bring this buying guide (also from Loughborough University) with you to make sure that your new car will be able to fit you and not cause you pain!
Return from Driving Ergonomics to Proper Sitting Posture.