my 2 grand kids love being pulled behind me
the 3 yr old usually crashes
her sister (5) only some times
I used to pull them pre-engine, and they did the same then
when their dad pulls them with his occ stingray with the long pipe, they say it smells bad
...my pipe is aimed straight at the ground in front of the engine, and they say they can't smell it
hope that helps
btw, the chopper pipe also spit oil all over the front of the trailer, I would be more worried about that hitting them than exhaust gases