I have a 2001 xk8. I have been having no problems with it. While driving at 70mph the engine shut off and displayed engine fail. When I tried to start it after pulling over the engine wouldn't restart. I had gone to a car wash about 2 hours earlier but it started without a problem 3 times after the car wash. Could this have something to do with my problem? Is there anything I can try before having it towed to the dealer?

Disconnect battery ,both connections and hold them togther for a minute then re connect the battery and try to start it again ,if it doesnt start then dealer only ,sorry i couldnt be of any more help but these new cars from 2000 on are getting so complicated with encrypted software and a sensor for anything and everything with all this geeky encrypted software as well ,plus copyrighted OBDII pin layouts us general mechanics will soon be dinasaurs and extinct which is what the dealers want so they can charge what they like and you cant do nothing about it.