did ur car CRANK wen u tried to start it?
the same thing happend to my car and my uncles car, he has e320 i have c220. Both was running smooth and all of a sudden didnt start, but the battery were fine. for mine everytime i jump start it it would be fine so i thouhgt it was a dead battery. so i go to the dealership to pick up a new one.. it was fine for 3 days, then it wouldnt start again!! so i think sh!@.. its not battery and something big. so i return the battery and make an appointment for checkup 2 weeks later. for the 2 weeks i was afraid to turn my car off too much, i kept on having to jumpstart it.. and its not good to jump start german cars apparentyl because it mite fry the computer? so the night b4 comes for my checkup ... then guess wat the car turned on by itself.. so i skipped checkup.. and ever since then the car starts fine... both my car and my uncles had the same problem.. and both fixed themselves...??? its alive?
one person suggested it was the alternator.. $$$$$ good thing it fixed itself or i woulda be that much poorer.
so my suggestion is try the car out for 3 weeks.. mine was lieke this for 2.5 weeks.. just have a jumper cable ready just in case
and if it fix itself then u're in luck!