None of the cars have acted yet. First of all, there is an advantage to passing on the inside (represented by the scrap along the left side of the road.) C has a good chance of passing B. But how good is B at passing? Even if C is better than B, C must consider how B compares to A. Is A better than B? In that case, he may hold off B's pass attempt, allowing C his own chance to pass. C has made a good decision, setting up with great position on the inside of B.
But if B is better than A and succeeds in passing, A will drop back a spot and block C. In that case, C should have taken the outside lane for his pass attempt. He would have been at the disadvantage for making a pass on the outside, but he would at least have gotten that chance. Racing on the inside has its advantages, but you risk being boxed in. Never rule out those outside lanes.
So it's important to consider not only your own position in relation to your nearest opponents, but you must also measure how well your opponents will race against each other and how those results will affect your positioning.
D's plan is to not only draft and gain a little momentum, but also to make a pass attempt and gain position all on the same turn. But how can he accomplish this? He's out of position!
D has done his homework: He knows that C is the best passer on the track. D is guessing that C will succeed in his pass attempt against B. B will drop back a spot (remaining in the same lane,) and C will move ahead clearing the way for D to make a pass against B.
Not only does D get to make a pass attempt, but he has also drafted C, gaining just enough momentum to negate B's advantage on the inside. D knows his opponents well and has given himself a great chance at gaining position and momentum because of it.
(Though, C could might have bluffed and not made any pass attempt at all, blocking D. But this would not be likely. If you choose not to pass, you should draft and gain some of those precious bonus dice.)
What's going on in Example 3??
They know A has lost a lot of momentum and, just like in Example 2, are hedging their bets that the car in front of them will be successful in their pass attempt, clearing the way for the next car to pass. (And C and D have also managed to gain momentum just like in Example 2.)
It's important to watch for those cars who have weakened themselves, those who have made the most passing attempts, shooting and/or bashing rolls. In Machinas, it is important to be aggressive, but you must balance action with moments of inactivity -- moments you can use to gain bonus dice to use for your next action.
For example, if you're better passing on a turn, consider drafting during the straightaways. If you must pass on the straights, try not using any bonus dice, saving those for sure passes on the turns.
If you go for pass attempts every chance you get, and use bonus dice during all of those attempts, you might easily gain first place, but you may not last to the end of the race. Save the all-out racing for the end of the race. Chances are, that is what everyone else will be doing. Don't get left behind.