This exact same problem just happened to me. Original owner of my 2014 SI didn't torque down the rear motor mount bolts after he put a Hasport in(caused a myriad of problems, broken off exhaust studs, serpentine belt got chunked out, etc.), which lead to my replacing all mounts with Innovative, just to be safe. After getting the mounts back in, the starter just clicked, and the system would not turn back off after trying to start unless I disconnected the battery. I checked fuses and all electrical systems I could touch, no visible problems, other than that the ground wire on the passenger side was now going body to body rather than body to mount, and the driver's side ground wire was going body to transmission, I replaced the starter (God help me I'm not going back through that to put the old one back on even though it's probably good), did the same clicking at first, then I heard a decently loud electrical short sound, continuous until I disconnected the battery, now no power to systems at all, the only light on is the security light on the head unit. I will update as the saga continues. Haven't even gotten to drive the car 100 miles yet thanks to the last idiot, combined with my own stupidity in not reconnecting the ground wires in a proper way.