Are you still having a 'hard start' on your g37?
I also have an 08 G37s with 90 miles on it and I have been having this same issue for over a year now. I have replaces spark plugs, air intake boots an filters. Were you to come to a conclusion?
I though it may have been my fuel pump as well, how did they come to the assumption the wiring was wrong? Shouldn't that be a recall on the vehicle?