Does anyone have knowledge regarding a Prevost that is being marketed as a 2009 yet has the exhaust exiting at the rear bumper level as opposed to the other 2009's that have the exhaust exiting through the roof?

Was it just an in line exhaust switch or is the chassis indeed different? I realize that the 2009 designation is the coach builders prerogative; however is there a VIN number that "starts" the 2009 model?