I'm trading in the P5 for a RX-8 this spring and am wondering what I should expect. As far as the cold start procedure, how they get around in the snow and anything else my wife should know about since this will be her daily driver?

 

get snow tires for winter. Redline is your friend in the summer!

 

I've never had a cold start problem. I move the car in and out of the driveway without warming it up or any of the other tricks to prevent flooding. It has never been a problem for me.
Blue is correct. Winter tires or at least All-Season tires are neccessary in the winter. The tires that come with the car are Summer Performance tires. And when they say summer, they mean summer. If there is the least bit of snow on the road, you can't get traction. My first winter with the car, I did 120 mph in my driveway. The tires were spinning and I wasn't going anywhere.

 

tell your wife to learn to heel-toe and join us at the track in spring!

 

I'm actually a newbie here as well, but I can speak specifically to your situation, I just traded in my 02 P5 in mid november for my 8 - the other posts are right on - snow tires are the first thing I bought (Dunlop M3's on Kazera KZ-A's 18's) As far as snow driving, my 8 with new shoes does as well or better than my P5 with Dunlop all-seasons did. No cold start issues to date - just gotta be nice to the engine while she warms up. The 8 does feel a bit different to me on ice (like any rwd would) than the fwd P5 did...oh, and plan to spend more money washing it...it's just not right to have a salty 8...