even if a car was thrown from behind kenshin he would probably catch on seeing as his senses and reflexes seem to be inhuman. and with soemthign the size of a car he would jump over it out of the way and return to his stance. also if they were standing close to eachother even a rock he would probably get out of its way instead of blocking it with his sword.

and i just think even with the force speed kenshin is faster. and in a battle where the first blow is the vital blow then i would think speed is the main importance well that and not missing.

also i coudlnt imagine vader being too much past 40. it depends how old luke is really. because he was young at the end of episode 3 and luke had jsut been born.