This is some sort of rubber stop on the trunk lift mechanism. Mine are starting to look worn out and I was going to replace them before they split. The part number 844A9 is $150 at Infiniti which is outrageous for a rubber bumper! I'm going to find an optional replacement but wanted to see if anyone else has done this before.

 

Here is the part...

 

$150!?!?!?! That's outrageous! If it isn't broken don't fix it lol I'd rather color it in with a sharpie marker then pay that kind of money