Greddy Type-S Coilovers on a 2006 g35 coupe

I had a body shop fix a scratch on my front bumper, gave them my wheels and oil to change free of charge.

My previous wheels were almost flush with the fender, these stock wheels are tucked in the rear by like 20mm. So.. the front of these stock 06 rays are pretty flush due to 15mm spacers, but the rears are tucked like crazy. (Not sure if this info helps...)

But after returning to these stock wheels, I have started to notice squeaky sounds when going over bumps and turning at wider angles.

Squeaks happened one day after the changes.

When I jump and push down onto my trunk (inside rubber trim), I can clearly hear the squeak. I did this to make sure I am not hearing things and going crazy.

Could it be due to the cold weather + coincidence? Like one day right after I changed my wheels, this started happening? Or did the body shop screw me over?