Being self employed and applying for car finance...

I was just wondering how difficult it is to get car finance now I'm self employed?!
I want to change my car but I'm a bit worried I won't get accepted for the finance, even though I'm paying it at the moment! What documents could I use to prove my earning etc.
any advise would be great :) thanks x

I got finance on a car earlier this year with no problems at all. Took with me bank statements, home bill and driving licence. The fact that I am self employed wasn't an issue at all.

That's good to know, thanks chick :)