I have a problem.  I have a 328i 2011 3L convertible/hardtop.  my granddaughter drove my car to her went came right back and wouldn't start.  I went to her house to see what it was going to be to fix it.  The car did nothing.  I assumed it was the starter so I bought one.  no go.  .no power to the starter so I bought  new ignition.   No go  .I then I bought a new battery.  No go.  My wife and I just went out to just try it one more time.  No go  but we did find one thing the key fob was very hard to take out.     I had to really had to pull it to come out .   I really need this car to run.  Is their anyone out there who knows enough to get me going

Hi Roger 

Obviously difficult to diagnose blind but throwing parts at the problem is an expensive way to fix it.

When you put the key in the ignition and turn it do the dash lights come on? If they do try putting the car in Neutral and starting (could be the inhibitor on the gearshift) It could be the Power Relay or the Starter Relay. Have all main power fuses been checked? Under the bonnet(Hood) you should have a couple of charging point connections can you measure power there?

To be sure you need a diagnostic scan by someone with a BMW capable diagnostic program. A good website for you is wwwpelicanparts.com they have an excellent reputation a great help section and How Too's with pictures.

Hope this helps 

Dave

When you say it does nothing, do you mean it won’t start? Does the dash lights etc come on?