As well all know, driving with the rear window aloft draws exhaust fumes into the car. It would be nice to find a solution for this issue.

I have a 2016 GX and have tried various window configurations and I still smell exhaust. It’s most tolerable with the sunroof open - I think the exhaust is sucked out over my head.

There are plenty of solutions discussed in 4RUNNER forums. Diverting exhaust to the side or even diverting it downwards.

If you have a GX and have done this successfully, please share your solution.

Also new to the forum and not sure if there is already a thread on this...

Thanks!

 

What about directing the exhaust out to the right side instead of the rear?

I've heard of some doing this as well to eliminate rear carrier combustible issues.

EDIT: Too quick a scan of your post.. that idea is already on your radar :-)

 

Clearly physics creates a low pressure zone behind the vehicle that cannot be eliminated. Yes, the exhaust can be directed differently ... but some fumes will invariably be drawn into this low pressure zone. As I'm sure you know, CO is odorless ... silent and deadly ... so don't use "smelling fumes" as your measure.

With the rear window open, opening side windows or the sunroof will only create additional "draw" into the cabin from this low pressure zone. So unless you like to play "what if" with your brain cells, it is best to leave the rear window closed while in motion.

 

I suppose possible some fumes are coming in through the following baffle as well except on the passenger side.

 

This subject predates GX's and even Lexus. Suburbans came out in 1935 and station wagons
have had roll down or flip open rear panels ever since. Old Husbands Tale was to run the HVAC
fan at high speed to pressurize the cabin... We were in the third row facing backward and Dad
could not see our blue lips, right?

 

I am actually surprised that "The Nanny State" has not imposed a Warning Light and/or Buzzer ... or even an ignition disable feature to prevent "the consumer" from driving with the rear window open. I guess falling asleep while driving (and killing off an entire family) is not as dramatic as the motivation behind TPMS being imposed on the public.

 

some ideas, seems like there's so many solutions
put up a barrier right behind the front seats. use something like an expandable foam sealant around the edges. make the top half Plexiglas so you can see out the back.
wear some scuba gear
add a snorkel, and have the air from that intake blast right into your mouth
get an oxygen generating unit or tank, like small aircraft use
pass a law that the exhaust is not allowed to enter through the rear window, ever. maybe some protests could work.
have the exhaust go in through the sunroof, then it has to go out the back instead of in from the back
put in an electric traction drive system an only use that when you want the window down.
get a few (3 or more) religious idol statues and affix them on the dash. make sure to get the correct ones.
do you have any crystals? pyramids? put those on the dash also.
since were talking a Japanese vehicle, look up Takeyari.
/s

even though some of the above may actually work, there's really no good, reasonably practicable solution.
you will have cellular damage well before you notice any symptoms.
you will have cellular damage well before you 'smell' any of the other chemicals in the cocktail you inhale.