This is sortof on-topic with the "unchangable" thread, and if Warranted, I'll move the discussion on this back there... just didn't want to clutter up that thread.

Scanners, as is, seem to work by magic in the freelancer universe. If you're within scanner range, and you're a big enough target (some things, once found, never leave scanner range), you show up on the targets list.

Now, if we assume that scanners are a combination of Passive radar and magnetic anomoly detectors, which goes active with some sort of penetrating radar when scanning cargo, it would be obvious to assume they can be "spoofed" two ideas that immediately present themselves are:
1) making your ship seem like a harder target than it really is (Ie: making a freighter show up on scanners as a capship)
or
2) making your ship drop off scanners by powering down non-essential systems and hiding in the "shadow" of a larger target. Examples: Hiding in asteroids with weapons off and engine killed, essentially just running life support (actually IN an asteroid, not just the field, but that would work too) to escape detection/launch an ambush; clamping onto a capship gathering intelligence data and then drifting off as space-junk before powering up systems and boogying.
These are classic scenarios in space movies/books. It would take some doing to get it in there, but it would really enhance the game experience.