What are the obvious signs that Jeremy Mayfield is a methamphetamine user?

I keep reading that Mayfield shows obvious signs of meth use. It's not obvious to me.
Do you see the signs? If so, please point me out to me. Thanks in advance.
Oops, I meant point THEM out to me. That probably makes more sense. lol
I know he's not the greatest driver in the world. I want to know why people say he's so obviously a user.
LOL Jocko. His lawyer makes Mayfield looks straight as an arrow!

: http://alcoholdrugstreatment.info/what-are-the-obvious-signs-that-jeremy-mayfield-is-a-methamphetamine-user