It is hard for me to discuss about price or discount, as we had a trade-in, down payment, and took some options (towing, wheel/tire, extended warranty, carpet). We negotiated on the monthly payments, so I don't know if the dealer actually gave us any discount, or a good value for the trade-in.
Bottom line is that I did some research about the market value of our current (previous) car, and came up with a budget based on that. We're actually paying less than what I budgeted, so we're pretty happy about it.
As for the tires, they are 245/60R18. I actually wanted 265/55R18, but couldn't find the wheels that would fit the tire size.