Today we installed a REM tunnel brace on my 300C SRT8. It is a great looking piece and gives plenty of room for the exhaust to clear without any close contact (rattle). Here are some pics ... Stock Brace: REM Brace: If you want to pick up one for your 300, Charger or Magnum we have them: http://www.bmcspeedshop.com/product_p/306-5015.htm
What exactly do they do just curios. Im having a problem right now with my Borla exhaust hitting my rear diff since I lowered the jeep and its driving me crazy.
This gives clearance for larger pipes and also provides a bit of strength side-to-side. Usually people add this to fix the rattle from the exhaust hitting the stock bar.
It is so nice to not have to feel/hear the exhaust hit that brace anymore when you hit bumps. LT guys and 3" exhaust guys would probably benefit from this. plus it does look better. and takes 3 seconds to put on lol.