We were driving on old RT66 aprox. 20 miles east of Amboy, CA. My wife spotted it first headed toward us leaving the east and heading s/w. A very bright chrome colored glare traveling at incredible speed (300-700 mph) 100-150 ft above the ground in the very same altitude making two slight direction changes at straight angles. It came within 200 ft of us so we got a VERY GOOD and CLOSE look at it, it was disk shaped but it continually changed shape in a combination of flat faceted forms. Its low altitude, ability to make straight angle turns, appearance, and INCREDIBLE speed just doesn't appear to be ANYTHING of Earthly technology.