Symptoms - The car cranks but does not start. I have had the car into the dealer 3 times and purchased spare relays and spare fuse box from them. Car became very unreliable...never knew when it was going to start. I replaced fuel pump relays 8 times until my third (and hope final) visit to dealer (Barnes Wheaton GM in South Surrey BC). Total bill so far about US$1700. 1st visit (Sep 15 2015)- they replaced fuel pump and relay. Car ran until..... 2nd visit (Dec 01 2015) - they replaced fuse box with used fuse box from Detroit because GM did not have any new ones at any warehouse!!! They read bulletin 15-NA-051 that referred to fuel pump relay problems due to rear seat clip and modified seat clip so it no longer protruded into fuse box cover. After this visit whenever the car kept on cranking past the usual quick start, I would stop cranking right away and check the fuel pump relay which was always fried. This happened about ~5 times until..... Jun 22 2016 - Visited dealer (after my phone calls not answered) to discuss repeated problem and possible causes with Barnes Wheaton Service Manager - he reviewed the problem with me for 1+ hours and found a deep mark in fuse box cover that indicated that the used fuse box installed in my car on Dec 01 had been in contact with the seat clip probably before being installed in my car (since the seat clip in my car had already been trimmed back.) 3rd visit ( Jun 23 2016) - they checked wiring between fuse box and fuel pump carefully at my request and replaced the used fuse box with new one I had purchased to keep on hand due to unreliable starts. So far after 10 starts it still works and I am a little bit more confident that we have found the problem (damaged fuse box terminal due to seat clip?), but only time will tell. One independent local mechanic mentioned that he had replaced fuel pumps etc regularly (1/week) because of poor quality gas available near our area. To eliminate this as a possible cause I have changed to super premium (no ethanol) to eliminate this as a possible cause. GM's lack of interest in this problem is disgusting...I have read over 60 complaints for this car from 2006-2011 models and no doubt this is a small sample. It is the most common complaint for the Lucerne on websites like this. Also: --The bulletin re the seat clip is not available publicly online, This is an easy home handyman fix and would save much frustration and dollars. -- Despite the fact that this was a common and serious problem with this car, GM did not stock new replacement fuse boxes. This prolonged my problem.