Standing room only may be the rule as hybrid hunters line up outside Toyota showrooms to join the ever-growing waiting list for a new Prius.

But not every Prius owner is smiling. Disillusioned Prius owners routinely report their view of the hybrid's dark side to ConsumerAffairs.com.

Recent complaints settled into several areas: unintended acceleration, troublesome traction control, battery failure, trouble filling the fuel tank, unusual tire wear and relatively poor gasoline mileage.

Unintended acceleration

An Eagle, Colorado, Prius owner reported this story: "On August 10, my wife experienced an unintended acceleration of our Prius resulting in a totaled car and long-term minor injuries for her.

Toyota has repeatedly blamed unintended acceleration with the Prius on faulty floor mats jamming the acceleration pedal.

"NHSTA has checked out our after-market floor mats which could have caused the problem but my wife claims that they were not the problem, that she looked at her feet to be sure they were on the brakes and the mats were still in their usual place as they had been for almost 10 months," our reader reported.

The tale of this runaway Prius is frightening. "I had to apply my brakes to keep the speed at 65 mph. I noticed that when I let up on the brake the car was starting to speed up even though I was not pressing on the accelerator," the driver said.

"No matter how hard I pressed on the brake, the car would not slow down. While keeping my right foot on the brake I slammed my left foot on the emergency brake." she said. "When I looked at the speedometer I was going 90 miles per hour."

The Prius barreled through a stop sign, and crashed through a grove of trees. "This whole time I had been pressing on both brakes, and the car was not slowing down at all. I felt the car tumbling and was aware of the air bags deploying. I finally came to a stop," the former Prius owner said.

Toyota's official position regarding the accident is that worn brakes are to blame, according to the owner of the totaled hybrid.

The owner said that is not true. "The brake shoes and pads were taken down to the shear metal in an attempt to stop this vehicle."

Runaway Priuses have been reported in California, Michigan, Colorado and Washington. The wreckage of the Colorado Prius is now in storage as possible evidence in a lawsuit.

Traction control

Pirus owners in cold and snowy regions report the traction control system in the hybrid is unable to cope with even a slight snow-covered incline.

Some Prius owners suggest the traction control is intentionally designed to prevent wheel spin that might damage the hybrid's electric motor. The corporate position from Toyota on Prius traction control is to deny there is a problem.

One California Prius owner finds the Toyota excuse to be absurd. On June 12, he discovered the dark side of his hybrid.

"The traction control system on my 2008 Toyota Prius is worthless. I have a steep gravel driveway that is extremely hard to climb due to the unnecessary engine cut outs, especially if there is any extra weight in the rear of the car," he said.

"Had I known about the problem with this earlier, as I have just found reported on the Internet, I would not have purchased this car."

A second Prius owner reported a similar traction control issue.

"In snow or ice conditions the wheels lock up due to the traction control system and leave me stranded," he said. "Almost resulted in my car sliding from a stand still off the side of the road down an embankment. This is dangerous and modifications need to be done to the computer software to allow more control for snowy or icy conditions."

Battery failure

More than one Prius owner has returned from a business trip or vacation to find their hybrid dead in the garage with no power and unable to start.

Jump-starting the Prius can be tricky. The enormous and expensive main battery is easily damaged and convincing Toyota to replace the battery is difficult, as an Idaho owner discovered June 3.

"My new 2007 Prius Toyota with 5,000 miles on it quit running, would not start. Called dealer and had maintenance department walk me through a jump start as with these cars you do it under the front hood not in the back where the battery is," she said.

"Car still would not start. They said have it towed in. I did have it towed in the 85 miles to the dealer. After several calls and two different reports on my car I found out they will not fix under warranty. They say I jumped it wrong. They say I caused the damage and that warranty is only for defective parts," she told ConsumerAffairs.Com.

The repair bill is a whopper "They want me to pay a minimum of $4,800 and maybe the towing. I bought this car because of the high maintenance rating and know look what a mess I am in."

Refueling

A Woodland, Washington, Prius owner reported in June about the difficulty filling the hybrid's fuel tank.

"We stopped to fill up in Ashland, Oregon (the gas is pumped for you here) and thought the tank was full. After switching drivers, not quite 83 miles later, we were down to four clicks on the fuel gauge."

"Luckily, there was one last station before we headed into an area of no gas stations. I filled up and managed to nearly fill the tank," our reader reported.

The Washington State Prius owner reported the problem to Toyota. She was told unofficially that filling the Prius gas tank to the top "was becoming an issue, even though Toyota was not acknowledging it."

Toyota responded with an official reply June 11. "Well, it is official from Toyota Corporate, if you do happen to have challenges filling your gas tank there is no fix," our reader was told.

Toyota noted that 6 to 7 gallons at a fill-up is normal.

"We apologize with your dissatisfaction with the fuel tank bladder in your 2008 Prius," Toyota wrote. "As your case manager explained to you, this is the design of the fuel tank and there is no repair available to change the design."

Tire wear

Unusual and premature tire wear has troubled the Prius since the first hybrid arrived in the U.S. almost 8 years ago.

A Huntsburg, Ohio Prius owner reported the tire wear problem June 15 with his 2002 Prius. He is now on his third set of tires. "The tires are supposed to last 65,000 miles and neither Toyota nor Bridgestone will do anything about this potentially life threatening problem," he said. "We had the tires rotated, balanced and aligned as needed. In my opinion, if you want an environmentally friendly car, buy a Honda."

Poor gas mileage

Mileage claims for the Prius vary widely. At one time Toyota claimed 60 miles to a gallon when the electric motor was providing the majority of the hybrid's power. But so few Prius owners have obtained the 60 mpg that the Japanese automaker eventually backed off the claim, blaming the error on Environmental protection Agency fuel mileage testing.

A ConsumerAffairs.Com reader in Casper, Wyoming missed the Toyota retraction. "We just bought a used 2005 Prius and thought it would be great to get 60 miles to a gallon. Like others who hoped for 60 mpg we have been disappointed," he wrote.

"The onboard computer reads about 41 to 43 around town. I have not figured the mileage by the old fashioned way but my guess is it is less than the computer. We have had the vehicle for about a week and are thinking of selling it."