Hi Bob,
Regarding cleaning the windshield, I use a nylon mesh pad / squeegee attached to a telescoping paint pole for the outside. When at a a gas station, I use whatever cleaning solution is available, The squeegee is almost useless. When at camp, I use a collapsible bucket with lots of car wash solution + the windshield wipers.
For the inside, I use Windex with a touch of alcohol added and a triangular windshield cleaner tool/pad and paper towels Yes, you have to climb on the dash and, because she is a lot lighter, I let my wife do it.
Have not yet tried to open the microwave vent. Let me know when you find out.
Cheers - Old Navy