2008 V 8, and 2007 VR6. Got two car seats in the V 8 right now, both LATCH installed right and left. Used to have one in the middle (LATCH also, but using out left and right LATCH points). Now got rear facing passenger side and forward facing driver side. 2007 has same LATCH points but no seats in (daily driver/commuter for me).
Don't know what is going on for you. Older seat on one side (like out of older Treg? You have the LATCH emblem also only on one side?
Hope you got the hard child seat under cover, those save your seats! Got one pic of the brand I am happy with.