Buses leave from Stazione Marittima, the white building in the background in the link below. More likely you need to be at the departure point by 5-30pm, though I think it was after 6 before the buses left last time, takes 45mins to 1 hour on the circular tour to get to the stadium.
https://www.google.co.uk/maps/place...221f12ec543dbc7!8m2!3d40.8381465!4d14.2589849
That could be a disaster, stuck on bus for an hour, lets hope there is a toilet on it. I take it theres plenty pubs/bars in the area?
Anyone else on coach number 4 on the TC trip? Look out for the Scottish guy. :-)