How do I negotiate a lower price on a used car at a dealership?

[curiouslystrong42]

I'm particularly interested in a 2004 Saturn Ion 1 with 46,000 miles on it and a sticker price of $8000. The thing is, that's pretty much the very top of my price range - something more like $6000 would be a lot more managable (not that I really think I'd be able to get that). I know the Blue Book price is about $7925, but the trade-in value is something like $5500 (also according to Kelley Blue Book), so...

1. What's the lowest price I can reasonably expect to get?
2. Any tips for negotiating a lower price?

[Andrew Allison Adams]

bring a gun