I'm just a little bored sitting here at work with nothing to do.
I started thinking what else could I do to my car that
#1. is easy
#2. is cheap
#3. has proven benefits
#4. is fun (love tinkering)

So guys what have you done to your car that was cheap, easy to do and you see or feel benefits from?

Home made ingenuity, store bought, what ever it may be lets hear about it. And if its home made pics are encouraged!