Test drive, test drive, test drive ...
As for the salesperson, be up front and honest with them - what youre going to use the car for, what you want, who will be driving it, etc. Maybe the Corolla is a better fit ... maybe not. The Sales guys have two hats ... the 'product info' hat and the 'sales hat'. They dont get to put on the second hat unless they do a good job with the first.
As for negotiation ... the mark up is not that high on the Yaris/Corolla/Matrix anyways. So while there is room for negotiation, you will start at MSRP and go down a bit from there. Ive never heard of a Toyota dealer ask ABOVE MSRP on those vehicles, even if they are in high demand. The 'first quote' price will probably be right off the Toyota website.
Oh, and when negotiating, use accessories as barganing chips ... theyll much more likely to throw in $1500 worth of accessories than take $1500 off the price.
Hope that helps !
