Ooh, shiny new tires

For almost a week I've had a screw in one of my tires and have had to top off the air pressure almost daily.  When I finally got a bit of a break, I did about 2 solid hours of research to pick out a full set of replacements, since all of my treads were a little worse for wear.

When I called the local Wheel Works, much to my surprise, they had exactly the tires I wanted in stock. In fact, there was a 4 for the price of 3 special in their latest mailer!  (The guy on the phone actually swore I was looking at the mailer.)  I got the new set installed first thing the very next morning while I waited.

On my way to work, had an opportunity to test 'em out on a tightening S-curve offramp that has lots of runoff.  As I trail-braked into the tightening part, my back end suddenly let loose, out followed by fronts.  This, on a naturally understeering front-drive car.  I was able to save it, but yikes, that was a hairy moment.
 
I forgot that new tires need to be broken in.
 
My bad.