Arrive at Rome Airport around 9.00 am, don't have to leave until around 2 pm ish, maybe a bit later is possible.
Would it be feasible to hire car, dump bags in car, get train from airport to Pantheon, walk to Colosseum, walk to Trevi fountain (maybe), get train back to airport and away by 2 pm ish?
We're all good walkers, and would love to glimpse these sights but its got to be a fleeting visit or nothing! We know that we'll only get a brief taste of each place, but would prefer that to not seeing them at all.
We've flown in and out of Rome before, but never actually visited the city. DC is a classics student and would LOVE to see the Pantheon and Colosseum - we're just exploring the possibilities.