Hahahahahahaha...this post is so funny because I am exactly like you guys. I am a p*ssy when it comes to spiders.
Had one big mother crawling across my windscreen once. Don't know what spider it was, but it was freakin' huge! Couldn't get the thing off by swerving left and right. So drove down the Eastern at 120km/hr to try and force it off. Didn't bloody work!
Decided to just stop on a side street (made sure I was no where near my house) and chance it. Got out of the car, took out my golf umbrella and just brushed it off as hard as I could. Then quickly jumped back in the car and drove home.
I hate spiders...