Driver's seat is loose ('04 coupe)
 

Recently my driver's seat has started moving around a lot. The brackets holding it onto the floor are all tight and secure, but when i lean back the seat moves back and forth. It feels like whatever is securing the seat to the bracket is loose or something, or the reclining mechanism is loose, but I'm not sure. Anyone have any ideas on what this could be? Would I need to find a new seat?

same issue on my 04 - never found why, assuming there is some play in the guides that run the electric motor?? Not sure - but here hoping one of the old heads can tell us whats up? :)

Got it fixed today, posting what I had done for anyone else who runs into a similar issue like ArkansasG35COUPE.

Turns out part of the seat bracket was cracking pretty badly. Went to a bunch of different places, and one recommended I go see a welder to weld the broken pieces back together. Turns out a screw had also fallen out in my seat bracket assembly. The guy welded the bracket back together, put back in the midding screw, and went over all the other bolts/screws to ensure they're all right. Drove it home and seat now feels as solid as a rock.

Interesting! Mine squeaked for a while and I ended up pulling the seat and spray greasing some of the moving parts. Hasn't squeaked since 4 years ago.

There was a TSB released for this issue.

I was going to suggest to look for random screws/bolts that fell out but looks like the OP already resolved the issue.

Same situation.
 

The same thing happened to me. I had been feeling the seat get more and more loose to the point I didn't want to drive it anymore. I looked at the mounts and one of them is cracked so I will be taking it to a welder tomorrow. After I got the seat out I noticed the center bolt was missing which allowed the seat to move freely on the rail instead of being mounted to the threaded rod attached to the motor. The only thing that was holding it in position was the other side. Hopefully I'll be back in the G tomorrow. I'm thinking the stresses allowed by the movement is what resulted in the mount getting fractured.

I don't know whether to blame the car or the cookies I've been eating. I need to remember to put some thread lock on those bolts too. I'm happy these seats pull out easy.

Pictures for reference.
https://imgur.com/a/FNUR6dI