The first time this happened was July 2010 (5 months after I bought the car used) and happens intermittently, the most recent instance being 8/27/11. Once the electrical systems start bugging out (either parked or driving), the power steering goes out, and I have to immediately pull over as the battery dies quickly. During one of these fits, turning the steering wheel to the left or right cuts the power immediately. If I jump the car after it is dead, it will start, but it's a coin toss on whether or not it will run properly. I can also leave the car alone for awhile after it dies and at some point it will start up like nothing ever happened. Due to the intermittent nature, I cannot get a diagnostic. I just have to keep driving the thing and wondering if it will start and work properly. I have had the alternator tested and it is fine. I have changed out the battery and this did not solve the problem. There was a period of about 9 months (October 2010-June 2011) that I didn't have any problems at all, but no one can attribute the heat/humidity of the summer to a specific problem.

Okay, so you're driving along an interstate highway, cruising along at 70 and your engine suddenly loses power but then comes back with an annoying lurch as the injectors mysteriously cycle on and off. This happens for the next few miles, and your scared to death passengers can't really hear you explain how there's really nothing to worry about because they can't hear you over the repeated locking of the back hatch and the vehicle's alarm system. You decide you need to exit so you move over to the right lane, signaling with your blinker and end up close behind another vehicle. In their well polished tailgate you can see the reflection of your car's daytime running lamps cycling on and off. You signal to exit and you notice the exit ramp is a doozie that's gonna take you around 270 degrees on a sharp left hand turn just as soon as you get off the highway. You see the suggested speed for the exit is 25 and glance down at your speedometer as you're decelerating on the ramp, but it provides you with no assistance as it and the tach randomly bounce around between zero and redline. You slow down to a good appropriate speed and almost run into the guardrail as your electric power steering shuts off. You strain to compensate on the exit ramp's tight curve and almost run into the other side as it clicks back on moments later at dead-stop-with-my-wheels-buried-in-cement steering power. Your passengers are almost sure your car is possessed and the interior lights cycling on and off isn't really helping, the daytime running lamps are flashing out some sort of bizarre distress signal, the alarm just started going off again, the back door lock solenoid is clicking away, and according to your speedometer, while it may seem like you're at a dead stop in a McDonald's parking lot trying to find the horn fuse to shut the alarm up (not that that works anyway), you're actually going 130 and you're engine is at full-tilt redline, even though it's off.