I am with you Katie, I still think Gavin Lang is the best driver going around and he hardly moves, much less jump around. Chris Alford can get a bit animated at times and if my memory serves me correctly, Ted Demmler used to jump around. We need a driver to post and tell us what the 'jumpers' think they are achieving (forward momentum?). As for the leaning back like the Americans, I thought it may have stemmed from an alternative arm position - straight rather than bent.
ps Persist in having the stewards get back to YOU