Didn't say it was a rule... just said it's what I prefer.
You prefer lookin' thru a window.
No doubt many of us came from bikes that didn't have windshields. No misguided premises.

 

Don't use RainX unless you know for sure that it can be used on your shield. On some it will melt and make them cloudy. Harley makes a product that is safe to use on theirs.

I just use wax or a detail spray.

 

This is what I currently use, it works well: http://www.rainmagic.com/

When I run out I heard good things about raincoat. I'm going to give it a try:http://store.motosolutions.com/clearvision/A.html

 

Here are instructions from Clearview Shields for fitting a shield for looking over or through. Pros and cons of both. To each his own.

http://clearviewshields.com/shop/correctshield.php

I prefer to look over the shield. I have the Clearview Recurve 10.5" and I peak about 1.5" over the top. The recurve throws the airflow adequately above my head. And in fact when I lower my head to look through the shield there is virtually no difference.

I know that after the 360 miles I did today with all the bugs and grime I collected on that shield, it was difficult to see through it in the daylight. Add in some darkness and/or rain and I would not have ridden if I had to look through it. I have been caught in that situation before. It is blinding. Especially in the oncoming traffic's head lights.

Clearview authorizes the use of RainX on their shields. Some don't. I have used no better water repellant (so far) than the original RainX. The spray cleaner RainX you get in ChinaMart sucks. Get the original from an auto parts store. I use Novus to clean an polish then RainX it. Works great for me.

Clearview is made in USA.

Cheers,
Woolly

 

I use Pledge. I've been using pledge for years, and I know long-time commercial fishermen in Alaska who swear by it to polish the windshields on their fishing boats.

btw, I look over my windshield, even when it's raining. Go fast enough and the wind carries most of the rain right over the top of your helmet. You learn to look through the raindrops on your goggles. I ride in the rain a lot.

 

I use same wax as on the paint...Mcquires

Do not use anything if it is ammonia based...rainx, glasscleaner..etc

it "crazes" the plastic over time...
crazing is the little spider web like cracks you see over time

 

I'm from Texas...What is rain?

 

Amen brother! In West Texas it "Sands"!

 

Here is a excellent site regarding motorcycle windshields that may answer your questions in more detail from an expert;
http://allamericanprod.com/hints.html