Here is a product we got from www.dubflecta.co.uk
This summer Jed and his family were plagued by aggressive wasps on the tour they did of europe. With temperatures logged above 45*c driving around with the windows wound up was to prove a bloody pain in the backside so we have tried these nifty wind deflectors out. This way you can drive around without sucking the nasty wasps in or letting loads of rain in when driving in the rain with the windows down kind of a poor mans air con system. They are a good price and if you are in the UK you can buy them here, or if your from outside the UK do like it says in the Video and email JP mentioning Campervanculture and they will get back to you with a reasonable world wide shipping cost.
Personally I would have been chuffed if they were bought for me for my birthday or at Xmas and at only £30 per set what self respecting camper van owner wouldn’t? They do them for a wide range of other vehicles too as well as acrylic head light protectors, T4 and T5 bumper protectors, rear spoilers….