Hey guys, my first post as I've been following this site since before a bought my 09 xb in april. Big problem now. I've been experiancing a strange rattle when I accelerate the box. Strange thing is it doesn't happen everytime I accelerate and sometimes won't hear it unless I'm driving along parked cars and hear the echo. This is my first car and not sure of what to do as I'm not very knowledgeable with cars. I bought it from a non-toyota dealership used with 12,700 miles. Is this something to be concerned about? Should I go back to the dealership even if it isn't a toyota dealership? Will they honor the fact that scions are under warranty for 36k miles? Should I just go straight to a scion dealership? Has anyone else experianced this? Oh, one more thing, just to get an idea of what it sounds like, it sometimes sounds like its coming from the muffler and even makes the xb sound like it runs on diesel. Sorry for rambling, just real concerned. Thanks in advance.