yah, spycraft isn't a great fit... it also wasn't designed to be used with more then 2 vehilces...
The basic system I'd used would be a short little bit (maybe a side bar?) on using opposed skill checks as a Stunt.
Your being chased by a some one (or group of enemies) and you all have similar speeds (enough that you just can run away and they just can't over run you).
To try and get some space between you and them, you make a stunt... kind of like a complex stunt but with no armor class modifier. You set a DC for yourself. If you make it then they have to make it too, or you gain some distance on them (about 30') because you have two stunts per round, you could do this twice... and the best decription of these actions would be you making a fake turn in one direction or another etc to throw them off. If they fall for it and over turn etc then they have lost distance from you. ON their intitative they can attempt a stunt to out fly you and thus gain a bit of space (gain just 30') that uses the same mechanic. they set a DC and must beat it. If they do, they then you must also beat it or they gain a bit on you.
now if some one sets a DC for themselves, and then fails to reach it, nothing happens. If they fail by more then 5 then you lose control... and in some crowded areas that's dangerous (because a vessel out of control might collide with an asteroid, another vessel, canyon walls, etc).
something along these lines. of course I needs to be written out better. with a bit more thought.
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Now about the d20 class.... have your read D20 Modern yet? in it, all characters start with character classes based around a ability score (strong hero, dextrous hero, etc) and around 5th level they generaly become able to take "advanced classes" which are more like standard d&D classes. at around 10th level they become able to take Prestige classes. so, for example, a soldier, gunslinger, medic, spellcaster, etc... those are all Advanced classes. By that extention I'd say that a "core pilot" class in D20 Modern should be a form of advanced class as its to spicific to be 7th core class. mean while all our "prestige classes" will still be avalible in both games.
d20 modern is designed to start broad and let character become spicific over time.
The other option is instead of making it an advanced class, we make it a "carear package." It gives the basic flight feat, and pilot skill, etc.
Also, the topic of d20 Modern also brings up the thought of "wealth systems" we will need a way to provide a wealth modifier for each item or vehicle.
essentialy whay I'm saying is that d20 modern is a little off from D&D and we might want to adress this. d20 modern is OGC.
