The drag racing at Mizugama still happens on Thursday and Sunday night, as well as some "test 'n' tune" at Henza, out near Ikei. Think the drifting near the docks has moved on though after there was a crackdown on it.
Might be worth heading to
http://blacklinux.com/innersanctum/ and seeing if there's anyone you recognize there. There's a fair few old skool guys on there.