To look through the windshield in your dream represents what is ahead of you and the choices you make. It may also indicate that your approaching your goals in all the wrong way.
To dream that your windshield is broken or cracked indicates that you have a skewed perspective or outlook on things. You are experiencing many setbacks in the pursuit of your goals.
To dream that your windshield is fogged up suggests that you are not really expressing how you really feel.
To dream that your windshield is dirty indicates that you are confused or unclear about where you are headed in life.