I have had no issue with exhaust smell. Mike drove 30 mile round trip to high school many days last year. No exhaust smell. We seal up the cockpit to keep out engine bay heat.
If your smelling exhaust fumes. You need to fix it right away.
Carbon monoxide (CO) is a deadly, colorless, odorless, poisonous gas.
http://www.cpsc.gov/en/Safety-Educat...-and-Answers-/
Bob