HELP!!!! I'm borrowing my girlfriends 2012 Mercedes C350 and it won't start!

Did you try applying the brakes before trying to start. Some vehicles the brakes has to be applied before car will start or go into gear.

Yes I have tried that.

Try turning the key to the on position with foot on brake without trying to start and see it gear shifter can be put in neutral then try to start.

Does it have an alarm system ?

Sometimes a cell phone or other electronic device can interfere with the anti-theft. Make sure any such device is away from the key or fob.

So I think the problem is that when I try to start the car, the steering lock doesn't release, so the car won't start. I can't put the shifter into neutral either.

Maybe if I could figure a way to release the steering lock

Wiggle the steering wheel back and forth while trying to start it. Is it possible that the battery is low on charge or bad?

I have tried that too. I could be. I can't see why it would be because I left it for 30 minutes max. I'm also pretty sure I didn't leave anything on. All the electronics still work fine too

It may have to go to the Mercedes dealership for repair. They have had lots of issues with the steering lock according to some reading I did in the last few minutes.

Hmm I have read the thing as well. I can't believe this has happened! I'm the first person she's ever let borrow her car!

Let us know what happens, it might help someone else.

we had same issue they replaced steering lock now few months later its starting again any feedback?

This happened to me 3 or 4 times! Car just wouldn't start! After I called Mercedes to toe the vehicle and while I was sitting and waiting... I said to myself, what the hell let me try starting it one last time. I be dam the car started right up as if nothing ever happened!