330xi winter tires

hi everyone, i am new to this board. Now i have a question about winter wheels and tires. I am going to have to buy a set of winter tires for my 330xi with sport package. I have talked to technicians in the dealer and they said four wheel drive drive train needs different wheel design from their rear drive siblings, so what should i do?
should i just big the winter tires mounting and un mounting every year or
should i buy an xtra set of wheels?
and what is an economical way alternatively?
thanks for any comment!!!!

Didn't the 330xi sport package come with all-season tires? Are they not working out well for you in the snow?

no, the wheels and tires are the same as regular 330i
17inch M-design wheels with 17inch summer continental.
it's just that the other suspension components stays the same, higher than even regular cars.
my brother with those continental was skiing all over.:grey:

I have a 2001 325i with the sport package (225/45 R17 tires). I bought some Bridgestone Blizzak tires, which are snow tires of the rare 17" vareity. I put them just on the back drive wheels.
Here's my opinion:

Good in the snow.

Bad on the highway.
Downright scary handling - the car wanders from side to side at 65 MPH+. So that's the tradeoff with handling.

So if you go with snow tires, remember they will take their toll on handling.