I have a 2007 TBSS. I went to several muffler shops in Atlanta, GA. The shops told me it wasn't a good idea to put duals on because the pipe would cause the rubber on the air suspension bags to crack from the heat. One shop said the spare tire would need to be removed. Has anyone with duals had any issues with either issue:undecided? Is there a possiblity the shops are against this because they do not have the right equipment (mandrel bender)? Would it be best to get a pre-bent kit like Stainless Works,SLP or Borla?