Hey, cool car. In a nice bit of symmetry, I once had a BMW 2002, but you have a 2002 BMW. Get it?
Oh, boy. One of those days. Anyway, it would be great if you could get away with a single rack system. Ideal would be something from Thule (www.thule.com) or Yakima (www.yakima.com), a cross-bar system for the top of the car, with attachments for skis, boards, bike, etc. For instance, you could purchase a pair of Thule AeroFoots, LB50 bars, and a fit kit for your car. Add to that a Big Mouth Upright Bike Rack, 724 Flat Top ski/board carrier, and a Hang Two Surfboard Carrier. With locks for the rack, that would come to about $550. A regular cable lock can be used to tie the bike to the roof, although any determined crook can quickly separate the two.
I appreciate the fact you dont see yourself hefting a bike to the roof of the car, but dont dismiss the idea entirely. Depending on the bike it might be very do-able, particularly if you give yourself an assist with a small footstool or something. Its mostly a matter of leverage and balance, not brute strength. If you can grab your bikes frame and lift it to eye level, then you can get it up onto the roof of your Bimmer.
Otherwise, its a hitch or trunk mount for you. And you actually could fit everything onto a hitch except the surfboard. Figure $200 for an auto welding shop to attach a Class 2 hitch to your BMW. The Xport Free Loader bike rack, sold at Performance bike shops and on their web site (www.performancebike.com), goes for $100 and holds up to four bikes. Yakimas Little Horn 4 holds four bikes and is $160.
Youve got your winter gear, now get outside and use it. Away.coms ski and snowboard guide makes it easy to find nearby slopes just begging for fresh tracks.