I'll try and get on tomorrow night after work, (GMT+12) but my time zone doesn't exactly help with arranged times on ad-hoc party. Will post here when I get on.
Adhoc party with GT PSP can be a little confusing to begin with, especially the few times I've tried to trade/share cars, but not too bad, you get the hang of it after a few races.
I'm using a pair of Ethernet Powerline Adapters, they works brilliantly!
EDIT: Sorry, a friend who I hadn't seen in a few months turned up out of the blue so I haven't been able to get on Adhoc party tonight.