Squrilly rear end in rain - new tires, bad wheel bearing

[joshua6060]

Hi Guys, its been a rough week for the Boxster, had a new battery installed and new HRTZ II Tires, when I picked up the Boxtster from the Tire shop, the guy told me that I had a bad rear wheel bearing and its possible that it could be a rear hub making the noise also. The noise isn't too loud, but slightly noticeable. I heard the noise before but I just assumed it was from the bald tires..... anyway since picking up the Boxster I had driven the car in the interstate 3 times, twice on clear days and 1 day when it rained, on the rainy day, I noticed that my rear end was very squirlly fortunately as I slowed down to a speed that felt much safer and less squirlly (35mph) as I hit traffic. Does anyone have any idea if the bad wheel bearing would cause my rear end to feel less stable in the rain? Certainly it can't be because of the tires because they are 3 days old...... Any comments would be greatly appreciated