What It Is: Portable car-seat massagers aim to lessen the effects of traffic and bad drivers by kneading away your stress as you drive. The cushions are strapped or placed on any car seat, and are powered by the cigarette adapter. The massagers usually have several settings and muscle locations to choose from. Some of the massagers are heated.

How to Get It: HoMedics Ultimate Comfort 8-Motor Massager has a 30-second instant heat option and customized vibration massages for back, shoulders and thighs. It also comes in faux suede or shearling trim to match automotive interiors.

Hammacher Schlemmer's Heated Massage Seat Cushion applies pressure across the upper and lower back as well as thighs.

Brookstone's TheraSpa 10-Motor Massager has four intensity levels and three speeds targeting five massage zones.

The IZON In-Car Massager, which wraps across the headrest, vibrates in eight different rhythms that hit neck and head muscles.

The Conair Heated Back Massaging System vibrates and stimulates four massage points.

For the truly sore back, the Sports Imports Limited Car Massage & Heating System kit installs inside seats and can be ordered with six or eight "Relaxor" motors. The company claims the system's massages promote circulation, which may counter driver fatigue.

Story continued at WSJ.com