Usually it's about 20% less than the MSRP. Add 2-4% for the dealers overhead which makes their profit 16-18% if you pay MSRP. Most of the time the salesman will only know what the invoice cost is. (cost + overhead).
As a rule of thumb you should always be able to get at 10-13% off the MSRP. I have always started with 15% off the MSRP and worked into that ideal range. With the decline in SUV sales you may be able to do better than that.
I saw an ad last week that Dodge was selling their trucks for 40% of the MSRP!
good to edmunds.com or kbb.com, both show dealer invoice. In 2006 I paid ~29K for a similar sticker priced 4runner. These days I think you should be able to get it for ~27K.
If you're in socal, go to Longo Toyota, best prices around and i searched EVERYWHERE.