I have an 07 with V8 and have the sulphur smell real bad. It's not just with the rear window down either. If just the passenger rear window is cracked, the smell will come in.
I took it to the dealership today and mentioned the bad smell. The service writer tried to tell me that the only way it was covered under warranty was if the check engine light had come on with oxygen sensor issues. I told him that I didn't think that that was the case but that there was an emissions warranty/TSB that covered it. He said he would check and call me back. He called and said he searched and searched but couldn't find anything. I was then at my office and pulled the TSB up and gave him the number. He said he would call back again. He finally called back and said "boy was it ever tough, but that he had finally found it and that they would replace them under warranty". He tried every which way to get around it. Stealerships!!! Glad they are honoring it but they sure pulled some stunts trying to get out of it.
Keep an eye on them....many people will tell you whatever they think will will make it easier on them. Not just dealers either. (Last night the Apple store insisted and insisted that my phone was not under warranty even though I was positive it was ....I went out to my car, got the receipt and their tune changed. Funny thing is that when they emailed my receipt to me it had the correct expiration date listed as well confirming again that they had no idea....or were playing games???)