I believe he may be talking about the 1-2 shift under hard acceleration. I get a huge bang when I launch hard, have wheel spin (s mode, etc off)…when it shifts from 1st to second. I had a similar problem on my Focus. Was the engine shifting so much it made the exhaust smack the bottom of the car. I installed a poly dog bone and it stopped. I tried the same thing on this car and it still does it. But the bang is from the engine bay/firewall. I believe it's the engine mounts. At some point I'm going to poly fill the other two. Believe it will stop at that point.
And btw, in Auto mode under 40 mph, when I smash the gas and it down shifts I have zero traction...under 40mph. While in manual s mode.... I gain a tad more traction since it doesn't downshift slam.... cause I'm already in the correct gear.