The car that hit a tree and burst into flames Saturday, killing actor Paul Walker and his friend Roger Rodas, was so temperamental, even the manufacturer warned dealers it couldn’t “drive over a Foster Beer can that is lying on its side” without creating problems.

The pretty-to-look-at $500,000 Porsche Carrera GT apparently has all the disadvantages associated with professional race cars.

TMZ got a copy of a memo Porsche sent to dealers, outlining how every part of the car is sensitive — not just to road conditions, but to the skill (or lack thereof) of the driver.

Meanwhile, the Hollywood Reporter spoke with a motorsport professional in Santa Clarita the day Walker died who said the men were not on a joyride: “The whole premise of taking the car out for a drive was because something was wrong.”

The source, who wanted to remain anonymous, said the car kept stalling, so it was decided to take it around the block for a test spin. He said Rodas, the driver, was not the kind of person to go maximum speed on a small street.

The investigation continues.