I have an 05 AT Rx8 and it has a noticeable rattle when in drive. It is very noticeable at a drive thru being next to a wall and such. Could it be an idler arm or such? It has 85000 miles awaiting a tune up. Any input is appreciated. Thanks!

 

Could be a heat shield. That was my rattling problem anyways.

 

I would find the rattle before tuning.. Easier that way.

get a huge hose clamp and wrap it around the suspected part. Tighten in down and see if the rattle changes or goes away. Move as necessary. You are looking more for a change, than it going a way to find the offending item.