SOUL+ HAS ROTTEN EGG/EXHAUST SMELL COMING INTO THE CABIN AS VEHICLE IS DRIVEN. CANNOT BE DRIVEN WITH WINDOWS ALL THE WAY UP. DOESN'T MATTER IF AC/HEAT IS ON OR OFF. PERIODICALLY, SMELL COMES AND GOES AS IT IS DRIVEN. DOES NOT MATTER IF IT IS SURFACE STREETS OR HIGHWAY DRIVING...ALTHOUGH IT IS MORE PREVALENT AT 70+MPH. IRRITATES MY ASTHMA...LUNGS HURT AFTER DRIVING FOR A FEW MINUTES AND COUGHING PERSISTS ACCOMPANIED BY A HEADACHE. VEHICLE IS DRIVEN TO AND FROM WORK UNDER NORMAL CONDITIONS. IT WAS TAKEN IN TO BE SERVICED AND THE TECH TOLD ME TO USE ONLY TOP TIER FUELS. I HAVE USED THEM EXCLUSIVELY FOR SEVERAL WEEKS AND THE PROBLEM PERSISTS...SEEMS EVEN WORSE. APPEARS TO BE A LEAK IN THE EXHAUST SYSTEM BEFORE THE CATALYTIC CONVERTER AND/OR A BLOCKED CAT. I'M AFRAID TO DRIVE IT WITH THE WINDOWS DOWN. I TRIED TO DRIVE IT THREE HOURS AWAY TO VISIT FAMILY A MONTH AGO AND HAD TO KEEP THE WINDOWS DOWN OR MY DAUGHTER WOULD COMPLAIN OF THE SMELL. SINCE THIS HAS STARTED, THERE IS ALSO A MUSTY/DAMP SMELL WHEN THE CAR IS FIRST STARTED. VEHICLE IS GOING BACK IN TOMORROW MORNING. VEHICLE HAS APP. 7500 MILES ON IT...SO RELATIVELY NEW.