today I had my c280 sport 2000 when I went to get in it with my wife, it wouldn't start, it kept turning but nothing. my wife had her door open on the first try. after she shut it and I took out the key and back in. it still didn't start. I let it sit for half hour, I went out and it starts fine. is there a safety feature or something where it won't allow it to start? or do I have a potential problem? thanks