Rear windows in the A-van

Got a question for you.

When you have rear windows that you can open in a Dodge A then can you drive the van while them being open? Or are the exhaust fumes coming in? Or do they vent the air inside to outside and keep the air fresh?

My exhaust ends to the side before the rear wheel and in the beginning I had problems with the fumes coming in. Then my exhaust tip was underneath the van in the middle facing down. Insulating the rear door lower lock holes cured the problem but it could still be better. Now the air inside the van is ok but could be a little better. This is also why I modified the underneath exhaust to side exhaust.

I don't have rear windows that open now. Mine are original fixed. I'm just wondering if I were able to find all related parts to make my rear windows open then would it be better or worse fumewize?

Iv'e had the same as your having some times nothing and then sometimes it comes in, Try opening the vents under the dash if you haven't yet.

I have a 68 panel with side pipes and the fumes are bad even with front vents and windows open. I only open the rear windows when the van is sitting not moving. I am not sure that it matters where the exhaust is, the vacuum behind the van will bring it in.

That is what I was thinking it would do. So I will keep my fixed windows in place. I usually roll the driver side window all the way down when I drive. And I have tried the vents but seems that when the van has a bad day then everything comes in although not as much as before.

ANY vehicle with rearward windows that open and are open while driving are going to attract the exhaust smells.

if you have ever driven down a gravel or dusty road you will notice the back of any car, truck, or van will be much dirtier, always keep back windows closed while driving,

The only reason I was second guessing this topic was the air pressure coming inside from open driver window and the vents and possibly creating a draft inside from front to back while the car is moving. I've noticed the dirt buildup in the back after dusty roads. I just wanted to be sure.

You could actually go down the road with no windshield or side windows and the dirt and exhaust would still come in the back.

Yep low pressure area behind any big object pushing thru the air.
Any newer vehicle with an opening in the back will have a safety sticker warning of this. Our vans were built before this was done, but it still says this in the owner's manual. Something like - Only open rear vent windows when not moving.