How to set up your desk 

Sitting ergonomics, sitting posture
To modify for a car, your hands would go on the bottom of the steering wheel rather than on the keyboard and mouse.
Also consider the phone. If you are using the phone a lot ,you really should be using a headset or hands free speaker options.
phones should be on the opposite side of the mouse.
eg, right handed people will have the mouse on the right side of the keyboard and the phone to the Left side of the keyboard. This should make it less tempting to hold the phone in between your neck and shoulder (not good).