I recently bought a 2011 IS250c

When I open the trunk fully, has a bit of a wobble to it.

In other words, there is some play on the trunk lid when fully open.

Wondering if this is a common or I have something loose as I've never experienced a car's trunk lid have any play before.

 

There are a lot of hinges, some minor play is to be expected. Don't push it any way other than the way it is supposed to move - up and down.