Strange fix for trunk rattle

[ABMW]

Hi all,

During the last 12 months, I've owned a 2010 35D and a 2011 35D. Both had horribly loud trunk rattling, that started at around the 2,000 mile mark.

I'm running 20" 214s on the 2011 35D, and it was extremely loud. I checked the air pressure, and found my tires inflated to 30 psi cold. I inflated them to 42 psi, as I have a long trip coming up, and am going off the above 100 mph. psi. chart.

Not only does the car handle 50% better, but the trunk rattle is entirely gone. I mean 100% gone, instantly. I've been wracking my brain for days now trying to figure out how tire pressure could have an effect on the infamous trunk rattle so many of us are faced with.

It's almost like a plague for the E70s, but no matter what I throw at the vehicle it's gone. I do have adaptive drive. I'm wondering if the vehicle compensated its suspension in some manner, to adjust for the increased air pressure, or if the lower tire pressure was allowing the chassis to flex 1% or 2% more than it should, but those explanations are pretty far out there.

Anyone else have any thoughts or similar experiences?