I am experiencing an intermittent loss of power once every couple of weeks; twice while driving 65 on a busy highway, twice while traveling 30-40 mph. During the first episode, the engine light came on and there was a brief interruption of power, but I was able to continue driving. The next three times, the engine shut down completely. After pulling to the side of the road, I restarted the car without a problem and continued driving. I have had the fuel cutoff valve replaced (prior to the fourth episode which happened 1/4 mile from the dealer AFTER the replacement), checked battery, alternator, relays and computer test. Three dealers have said that unless they can experience the problem, there is nothing to fix. I can't replicate the problem while driving with their mechanics. Any guidance would be greatly appreciated as I am worried about losing power when I can't pull over to a shoulder to restart. Are there parts that could be defective without presenting a problem code? Please help! The car has been terrific in every way, and I'd like to remedy this ASAP.