the problems explained. >> there are a series of patterns emerging that cannot be explained. >> reporter: rhonda smith is one of those unexplained incidents, telling congress her runaway toyota lexus didn't have a stuck gas pedal or floor mat. >> i put it in all available gears including neutral. but then i put it in reverse and placed both feet on the break and i was going to have to put the car to the upcoming guardrail in order to prevent killing anyone else. >> reporter: this noisy electronics lab at the university of maryland's clark school of engineering is where professor mike peck specializes in laboratory controlled interference testing. he believes toyota still doesn't know what's causing the problems. most likely it's electronics. and that, he says, is a worse case scenario.