Easily calculate that ADSL type connection 512 kbps is necessary minimum for client, today it should not be a problem.
Situation is very different for host for which the necessary minimum is 20 Mbps upload (for highest smoothness).
But bigger problem may be with old computers which do not cope with many cars on track.
And one more thing, new physics - I do not think that LFS 0.6A will have a lower hardware requirements than LFS 0.5Z28.
So I see more technical problems (ie low FPS, synchronization problems, long delays, packet loss etc) than fun.