I just sold my Jeep a month ago to get something more reliable and my obvious choice was a 4runner mainly because of the rear window drop. The fumes only occur when I floor it so I usually roll the window up before I do. But I'd like to avoid that PITA.
Could putting a downward exiting exhaust tip help? Seems like a side exit may screw with the pipe mounts. I've also seen I can cut it right before the bend in the axle. Does this cause any problems in the future? Does having the fumes exit directly under the vehicle have any affects inside the cabin?