Hey Nobrakes: If it was shaking like a rattlesnake tail at crusing speed you need to run a close check on chassis and suspension. Start with swing arm bushings/bearing, wheels (spokes loose? wheel true?), tire balance, wheel bearings, head bearings, shocks, and frame. Any cracks or weak spots? A post a while back mentioned that the CB400 frame was prone to crack just ahead of the side stand bracket. You need to be sure the bike will stay rubber side down before trying a 100 mph run. As for cars blowing you off the road - that may just be inexperience with the bike. Once you have the chassis straightened out and get some seat time you'll get used to how the bike handles and feel a l ittle more comfortable with it. Enjoy the bike. Never ridden one but from everything I've read and heard it's a great one.