Re: 13 wk2 starting issues... Help.
I think it's what chaddn says. Mine is doing the same thing, it's in the dealer right now, I opted for the relay bypass, since I am out of warranty and have no $1,500 or so laying around to invest on a new TIPM. Plus, from what I learned so far, it´s a problem with the TIPMs in general, so you have no warranty it won't happen again with the new one (no new part number has been developed, it's the same and a prayer the new one won't fail).
I'd try the bypass and see how it goes, and maybe later, if you still feel like changing it you do.
In the mean time, what I did and seemed to work is to "try to start" the car as if you forgot to press the brake pedal; you will hear the fuel pumps working for a second, after that, put ignition switch to off and then try starting properly pressing the brake pedal. This seems to "wake" the faulty relay. Started every time with that trick. Let me know if I am just lucky or if it really works for everyone! Good luck.
(Note: mine is keyless start, so you first push and it goes from OFF-->ACC-->RUN (1st time no brake pedal); press again so it goes to OFF; and then press brake and start)