Aerodynamics

Perhaps a wrong title but I'm hoping someone can kindly elaborate; why is it when I drive in the rain the water barely slides off the windows and mirrors?
It makes it pretty difficult too see the surroundings (outside of front and back) when driving in bad weather.

This is my first SUV, sedans are different - perhaps this is how it is but I'd love to hear other thoughts.

I'm using Meguiar's car wash shampoo and conditioner, if that plays a role.

Thanks.