Noticed on my way home today I noticed a rattle sound from the back of the car almost sounds like the back seat was loose or maybe the spare tire, but it's not do y'all have any idea? I'm lowered on eibach sportlines with a BMR adjustable panhard bar

 

Check the over-axle exhaust pipes, one might be hitting the panhard support bracket

 

Ok thanks

 

check the locking nuts on the panhard bar, mine backed off and rattled.

 

Their is a stamped steel brace under the car. I noticed on my Stang that the bar was loose. It's like the one that connects the K-member up front.