ES model, no frills, has 312K. No other major problems for the life of the vehicle, but for the last few months, have been seeing slight loss of power while at speeds above 40-45, this lasts for less than a sec and then all is normal. Did a basic tune up..plugs, wires, oil, filters etc, and switched to premium gas. Seemed to improve the problem (less occurrences, but not the symptom) so I said I can live with it. This weekend, I'm driving at about 35mph and I experience complete loss of power..no lights on dash, everything off. I start to pull to the side of the road, and engine springs back to life, transmission is still in drive and vehicle accelerates. Get the same occurrence about 1/2 mile down the road..same thing, start to pull off and car springs back to life. Took it home, and next morning brought to dealer. They've had it for 2 days now and although they have seen the issue during test drive, they have no answer yet as to the problem. I don't think it's alternator as the car would drive till battery dies, but I have no skills troubleshooting shorts and/or relay issues. I also have never seen an auto transmission kick back in on its own without shift in park or N and restart of engine..Almost like push starting a manual transmission. Any ideas? Thanks in advance. Emujo99