I have a '03 Focus with 153,000 miles. while driving yesterday everything shut down. speedo went to zero , gas gage went to empty etc. so after pulling on the shoulder and putting it it to park the car died. after about 10 mins it started and every thing was fine so i came back home. the battery is brand new. it has also happened to my wife while she was driving but in her case the car didn't die she lost everything including the head lights etc. anyone have a clue as to what the problem might be ?

Thanks