I have a rattle in my 2006 s281-sc. I have it a 60-70 mph and 5th gear It sounds like its coming from the passenger floor board and its metallic like a heatshield. all bolts are in the tranny plate and all heatshields are tight has anyone else had these issues and if so how did you fix it?

 

If everything underneath looks tight and in place could it be the passenger seat? Maybe get someone to ride along in the back and listen it out.

 

I had a similar mystery rattle, found out it was the seat belt holder on the side of the passenger seat was not latched and would rattle. I hope it its something equally as simple for you.

 

Yep, x2 on the seat belt holder... Drove me nuts for about 2 weeks

 

this is definatley outside the car sounds like its by the front wheel

 

I had a similar rattle that developed after about 5K miles, turned out to be the inner fenderwell shield rattling against the front fender. No problems since, mine was more prevelant on bumpy roads at ~40mph though, not on the highway, so it may or may not be the same thing. But mine was definitely mettalic sounding as well.

Anyway, that's what popped into my head, check it out just in case!

 

Is it coming from the right front wheel area? Mine had that one too, it was some bolt on the upper control arm if I remember? You can find instructions for fixing it on here somewhere. Thats where I found them.