same as the other guys, when i was in rome in 2004, was expecting some some of "roman holiday" grand prix of 500s round the colesseum, reality, didnt see a single uno (had to wait for crete for that, and then was blasted by a tub in the central mountains!) on an old panda, plenty of new pandas and ypsilons, and despite best efforts, didnt see a single dealership, but we were staying right in the heart of the city, and didnt really venture out to the burbs.
i think like alex says, the turin burbs may be more productive, and i'm def thinking a cheapo sleazyjet flight for a dirty weekend in the north is on the cards for 2009, looking for machine shops, auro emporia, and what ever else the grimy backstreet of turin can throw up
edit : btw, get down to the "mouth of truth" early, crowds are mental from about 11am on, and the spanish steps are way overated, but nice, personally the back roads around the piazza navone and trevi are much nicer