Re-gapped my plugs to .035, this morning (torqued to 18 ft/lb). They were all .025 or less from the factory, and the difference is like night and day. Before, the engine got buzzy at high rpm, with noticeable power fall off. Now, the engine is smooth throughout the powerband, and there is more power at those higher rpms (3000 - 5000). It doesn't make the car a speed demon, but it's MUCH more responsive.
One other thing........My dealer is replacing my scratched B pillar covers with new ones painted a matte black. This will eliminate the vinyl tape which scratches WAY too easily, and shows fingerprints. They are doing it as a warranty job, and I was told this was elevated to GM for resolution. The dealer is bending over backwards to get this resolved, so I am pretty satisfied. I'll post before and after pics after they are replaced.
One other thing........My dealer is replacing my scratched B pillar covers with new ones painted a matte black. This will eliminate the vinyl tape which scratches WAY too easily, and shows fingerprints. They are doing it as a warranty job, and I was told this was elevated to GM for resolution. The dealer is bending over backwards to get this resolved, so I am pretty satisfied. I'll post before and after pics after they are replaced.