With the new net-dll by nfs42, I also have more interest into multiplayer again.
You should have a look at it, as it seems to develop quite well.

It has especially not the nasty overhead, that 3dgs produces
(various things, like checking that the same level is loaded on client and server,
requiering that the same skipt is used on both)
There are workarounds to that, but this is work I dont see should be nessecary.
You hate the native 3dgs funtions less than me...

But in case you offer a demo, to your project, I would be interrested to
see it running on a larger scale over the net.