D - I'll have to go with the majority here and say that 1/100 would not be fast enough. A car is one object where all the parts are moving at the same speed and in the same direction. Panning at relatively slow shutter speeds is great for those scenarios. In sports, you will have players making passes all around them and limbs and equipment will be flying everywhere in different directions and at different velocities, not to mention the other players. 1/100 will get you nothing more than a CF full of shots that could have been good. There will be exceptions where the chemistry will be right and you'll get a nice shot but I think 1/100 or even 1/125 is cutting it way too close. Anyway, just my 2 cents. Nice car shots, BTW! CW always does great stuff.