well,since it was dumped, I tried it and it is quite fun.
During a race, you can summon a monster that attacks either with a spread; a powerful, single blow or a rapid-fire wave (you don't get to chose).
The spells and traps are used as the itmes in games like Mario Kart, except traps must be set, just like the normal card game.
To do each of these actions, you need speed counters (obviously) and action points, that are floating orbs on the course.
To get more cards from your 15 card deck (no, this is not a typo), you just get them as you would get an item on Mario Kart: run into the card icon on the courses.
Also, lifepoints still play a role on this one, just a smaller one: when you are hit by an attack and you don't have a monster, you will get LP damage, when it reaches 0, you will stop for a while before being able to get back to the race.
Back to the monsters, you can't switch them from attack or defense mode. Both stats are active now: Attack is how much damage the monster does, Defense is an HP bar.
And, obviously, the one who gets to the goal first, wins.
EDIT: There are 3 modes in this game: Story (which follows 5D's story), Gran Prix (aka Championship mode) and free race mode.