How do some exceed 31 prim limit on Phys objects?

I 've heard there is a way to work beyond the 31 prim limit for physical objects. Does anyone know where I should look for this?

If you're talking about vehicles, the ones that seem to exceed the limit aren't physical vehicles.

Check out scripts like Jesrad Seraph's MultiMove.

There's no way to increase the actual physics limit. You can fake it, though, with some clever tricks. For high-prim vehicles, for example, the illusion is often created by attaching any extra prims to the avatar piloting the craft. The vehicle itself is only 31 prims or less, and the pilot is wearing all the rest. Since the pilot is seated in a fixed position relative the vehicle, all the attachments move in sync with it. The illusion is quite effective, visually, as long as nothing ever collides with the attachments.

Another way to do it is to use follow scripts. The parts of the vehicle that are not physical are scripted to follow the ones that are. Typically, there's a delay involved with this, though. The end result is kind of an inch-worm effect. The recent addition of Mono to the system might help smooth this out, since the scripts can run much faster.

One more trick is to make the entire vehicle non-physical, and have all the parts scripted to respond to setPosition commands.

Or you can just attach the entire thing to an avatar, and "pilot" it simply by walking around and flying.

OK thanks, I was aware of all those, the "report" I got must have been omitting some of the facts.

one of the ways to avoid ghosting of vehicle parts that are avatar attachments is to use either a larger invisible vehicle 'base' (so that it has collision) or use select parts at the edges of the vehicles frame for the same purpose, leaving the attached portion to fill in details.